Biology subjects

Wong, G. W.

Publications and source records attributed to Wong, G. W..

14 recordsLinked to original sources

bioRxiv2026

Reduced cerebral blood flow and metabolic rate trigger an adaptive mitochondrial remodeling program in a Down syndrome mouse model

Mitochondrial dysfunction is a central feature of Down syndrome (DS), yet how trisomy 21 affects brain bioenergetics across scales--from gene transcription to cellular function to whole-brain metabolism--remains poorly understood. Here, we use the Dp16(1)Yey/+ (abbreviated Dp16) DS mouse model, which carries ~115 triplicated gene orthologs of human chromosome 21, to address this major knowledge gap and to provide direct in vivo evidence of brain-wide metabolic deficit in DS. Using magnetic resonance imaging (MRI) approaches, we show that Dp16 mice have reduced cerebral blood flow and metabolic rate of oxygen, with effects more pronounced in males than in females. Despite the suppression of cerebral metabolic rate, mitochondrial respiratory capacity and ATP synthase activity are largely preserved across brain regions, with sex differences noted. Transcriptomic analyses reveal marked upregulation of mitochondrial OXPHOS genes and the convergence of biological pathways related to proteostasis and mitochondrial function across brain regions, with male cortex and female cerebellum showing the biggest change. Collectively, our data suggest that a brain-wide metabolic deficit in Dp16 mice triggers an adaptive mitochondrial remodeling program across the brain to support bioenergetic demands. This compensatory response, however, is insufficient to normalize the metabolic dysfunction in Dp16 mice. Our findings underscore the value of integrating functional assessments at the organismal and tissue levels with transcriptomic changes to gain a systems view of physiologic perturbations and adaptations in the DS brain which may influence phenotypic outcomes.

physiology↗

bioRxiv2026

Deep phenotyping and multi-omics analyses reveal systems-wide metabolic dysregulation in a refined trisomy mouse model of Down syndrome

Trisomy 21 or Down syndrome (DS) affects multi-organ systems across the lifespan. The presence of an extra chromosome, along with genome dosage imbalance due to triplicated genes, contributes to the DS phenotypes. Of the DS mouse models, few are aneuploid with a freely segregating extra chromosome. We previously showed that the aneuploid Ts65Dn mice exhibit metabolic deficits consistent with the metabolic profile of DS. However, the genotype-phenotype relationships in Ts65Dn mice are complicated by the presence of triplicated genes unrelated to human chromosome 21 (Hsa21). To address this issue, we leveraged a refined model, Ts66Yah, where the extra triplicated genes in Ts65Dn have been removed. Deep phenotyping and multi-omics analyses showed that Ts66Yah mice develop pronounced and widespread metabolic disturbances. Despite sexual dimorphism in weight gain, body temperature, lipid and lipoprotein profiles, hepatic injury and adipose fibrosis, both male and female Ts66Yah mice share a common phenotype of pronounced glucose intolerance and insulin resistance, reduced mitochondrial respiratory capacity in visceral fat, altered serum inflammatory cytokine profile, and dysregulated serum and liver metabolomes. Pan-tissue transcriptomes also reveal signatures of immune activation, disrupted metabolic processes and cellular respiration, altered cytokine signaling, enhanced oxidative stress, and extracellular matrix remodeling. These combined changes across tissues disrupt metabolic homeostasis more severely in Ts66Yah than in Ts65Dn mice. Several phenotypes, including glucose intolerance, insulin resistance, tissue fibrosis, and oxidative stress were further exacerbated by an obesogenic diet. This foundational data establishes Ts66Yah as a valuable reference model for the mechanistic and comparative study of metabolic dysfunction in DS.

physiology↗

bioRxiv2026

Gene dosage imbalance disrupts systemic metabolism in the Dp16 Down syndrome mouse model

Gene dosage imbalance resulting from an extra copy of human chromosome 21 (Hsa21) contributes to numerous clinical features in Down syndrome (DS). While dysregulated metabolism has long been noted in DS, the underlying cause is poorly understood and vastly understudied. To fill this critical knowledge gap, we conducted a comprehensive metabolic analysis of Dp(16)1Yey/+ mice (abbreviated Dp16), a segmental duplication model carrying [~]58% of the triplicated Hsa21 gene orthologs. Our multi-tissue transcriptomic analyses reveal shared and sex-specific increases in expression dosage of the triplicated genes in white and brown adipose tissues, liver, skeletal muscle, and hypothalamus. Despite sexual dimorphism in body weight, body temperature, food intake, and physical activity, Dp16 males and females share striking core phenotypes of pronounced insulin resistance, glucose intolerance, impaired lipid clearance, and dyslipidemia. Functional assessments, combined with biochemical, transcriptomic, and metabolomic analyses reveal tissue signatures of immune activation and a pro-inflammatory state, ER and oxidative stress, fibrosis, impaired glucose and fatty acid catabolism, altered lipid and bile acid profiles, and reduced mitochondrial respiratory capacity in Dp16 mice. These concerted changes disrupt homeostatic mechanisms that underpin metabolic health, contributing to systemic metabolic dysfunction. An obesogenic diet further exacerbates insulin resistance in Dp16 males and females despite divergent weight gain. The collective phenotypes broadly reflect the metabolic profile of DS. Our extensive molecular, biochemical, and physiological data provide an essential foundation for genetic dissection of dosage-sensitive genes affecting glucose and lipid metabolism, and for testing therapeutic strategies to improve metabolic outcomes in DS.

physiology↗

bioRxiv2024

Mitochondrial respiration atlas reveals differential changes in mitochondrial function across sex and age

Organ function declines with age, and large-scale transcriptomic analyses have highlighted differential aging trajectories across tissues. The mechanism underlying shared and organ-selective functional changes across the lifespan, however, still remains poorly understood. Given the central role of mitochondria in powering cellular processes needed to maintain tissue health, we therefore undertook a systematic assessment of respiratory activity across 33 different tissues in young (2.5 months) and old (20 months) mice of both sexes. Our high-resolution mitochondrial respiration atlas reveals: 1) within any group of mice, mitochondrial activity varies widely across tissues, with the highest values consistently seen in heart, brown fat, and kidney; 2) biological sex is a significant but minor contributor to mitochondrial respiration, and its contributions are tissue-specific, with major differences seen in the pancreas, stomach, and white adipose tissue; 3) age is a dominant factor affecting mitochondrial activity, especially across most brain regions, different fat depots, skeletal muscle groups, eyes, and different regions of the gastrointestinal tract; 4) age-effects can be sex- and tissue-specific, with some of the largest effects seen in pancreas, heart, adipose tissue, and skeletal muscle; and 5) while aging alters the functional trajectories of mitochondria in a majority of tissues, some are remarkably resilient to age-induced changes. Altogether, our data provide the most comprehensive compendium of mitochondrial respiration and illuminate functional signatures of aging across diverse tissues and organ systems.

systems biology↗

bioRxiv2023

Loss of CTRP10 results in female obesity with preserved metabolic health

Obesity is a major risk factor for type 2 diabetes, dyslipidemia, cardiovascular disease, and hypertension. Intriguingly, there is a subset of metabolically healthy obese (MHO) individuals who are seemingly able to maintain a healthy metabolic profile free of metabolic syndrome. The molecular underpinnings of MHO, however, are not well understood. Here, we report that CTRP10/C1QL2-deficient mice represent a unique female model of MHO. CTRP10 modulates weight gain in a striking and sexually dimorphic manner. Female, but not male, mice lacking CTRP10 develop obesity with age on a low-fat diet while maintaining an otherwise healthy metabolic profile. When fed an obesogenic diet, female Ctrp10 knockout (KO) mice show rapid weight gain. Despite pronounced obesity, Ctrp10 KO female mice do not develop steatosis, dyslipidemia, glucose intolerance, insulin resistance, oxidative stress, or low-grade inflammation. Obesity is largely uncoupled from metabolic dysregulation in female KO mice. Multi-tissue transcriptomic analyses highlighted gene expression changes and pathways associated with insulin-sensitive obesity. Transcriptional correlation of the differentially expressed gene (DEG) orthologous in humans also shows sex differences in gene connectivity within and across metabolic tissues, underscoring the conserved sex-dependent function of CTRP10. Collectively, our findings suggest that CTRP10 negatively regulates body weight in females, and that loss of CTRP10 results in benign obesity with largely preserved insulin sensitivity and metabolic health. This female MHO mouse model is valuable for understanding sex-biased mechanisms that uncouple obesity from metabolic dysfunction.

physiology↗

bioRxiv2023

Tmem263 deletion disrupts the GH/IGF-1 axis and causes dwarfism and impairs skeletal acquisition

Genome-wide association studies (GWAS) have identified a large number of candidate genes believed to affect longitudinal bone growth and bone mass. One of these candidate genes, TMEM263, encodes a poorly characterized plasma membrane protein. Single nucleotide polymorphisms in TMEM263 are associated with bone mineral density in humans and mutations are associated with dwarfism in chicken and severe skeletal dysplasia in at least one human fetus. Whether this genotype-phenotype relationship is causal, however, remains unclear. Here, we determine whether and how TMEM263 is required for postnatal growth. Deletion of the Tmem263 gene in mice causes severe postnatal growth failure, proportional dwarfism, and impaired skeletal acquisition. Mice lacking Tmem263 show no differences in body weight within the first two weeks of postnatal life. However, by P21 there is a dramatic growth deficit due to a disrupted GH/IGF-1 axis, which is critical for longitudinal bone growth. Tmem263-null mice have low circulating IGF-1 levels and pronounced reductions in bone mass and growth plate length. The low serum IGF-1 in Tmem263-null mice is associated with reduced hepatic GH receptor (GHR) expression and GH-induced JAK2/STAT5 signaling. A deficit in GH signaling dramatically alters GH-regulated genes and feminizes the liver transcriptome of Tmem263-null male mice, with their expression profile resembling a wild-type female, hypophysectomized male, and Stat5b-null male mice. Collectively, our data validates the causal role for Tmem263 in regulating postnatal growth and raises the possibility that rare mutations or variants of TMEM263 may potentially cause GH insensitivity and impair linear growth.

physiology↗

bioRxiv2023

Hypermetabolism in mice carrying a near complete human chromosome 21

The consequences of aneuploidy have traditionally been studied in cell and animal models in which the extrachromosomal DNA is from the same species. Here, we explore a fundamental question concerning the impact of aneuploidy on systemic metabolism using a non-mosaic transchromosomic mouse model (TcMAC21) carrying a near complete human chromosome 21. Independent of diets and housing temperatures, TcMAC21 mice consume more calories, are hyperactive and hypermetabolic, remain consistently lean and profoundly insulin sensitive, and have a higher body temperature. The hypermetabolism and elevated thermogenesis are due to sarcolipin overexpression in the skeletal muscle, resulting in futile sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) activity and energy dissipation. Mitochondrial respiration is also markedly increased in skeletal muscle to meet the high ATP demand created by the futile cycle. This serendipitous discovery provides proof-of-concept that sarcolipin-mediated thermogenesis via uncoupling of the SERCA pump can be harnessed to promote energy expenditure and metabolic health.

physiology↗

bioRxiv2022

Adipokine C1q/Tumor necrosis factor-related protein 3 (CTRP3) Attenuates Intestinal Inflammation via Histone Deacetylase Sirtuin 1 (SIRT1)/NF-κB Signaling

BACKGROUND & AIMSThe adipokine C1q/tumor necrosis factor-related protein 3 (CTRP3) has anti-inflammatory effects in several non-intestinal disorders. Although CTRP3 is reduced in the serum of patients with inflammatory bowel disease (IBD), its function in IBD has not been established. We aimed to elucidate the function of CTRP3 and related molecular mechanisms in intestinal inflammation using a colitis model of genetically-modified CTRP3 mice and intestinal epithelial tissue from patients with Crohns disease (CD), one of the two main forms of IBD. METHODSCTRP3 knockout (KO) and overexpressing transgenic (Tg) mice along with their corresponding wild-type (WT) littermates were subjected to drinking water containing dextran sulfate sodium (DSS) for 6-10 days to induce acute colitis. Mouse colitis symptoms and histological data were analyzed. CTRP3-mediated signaling was examined in the intestinal tissue of mice and patients with CD. RESULTSCTRP3 mRNA and protein were detected in murine and human intestinal epithelial cells, as well as in murine intestinal smooth muscle cells and mesenteric fat. In DSS-induced acute colitis models, CTRP3 KO mice developed more severe colitis than their WT littermates, while CTRP3 overexpressing Tg mice developed less severe colitis than their WT littermates. In both water- and DSS-treated CTRP3 KO mice, reduced CTRP3 levels correlated with decreased levels of Sirtuin 1 (SIRT1), a histone deacetylase, increased levels of phosphorylated nuclear factor kappa B (NF-{kappa}B) subunit p65, resulting in increased expression of pro-inflammatory cytokines tumor necrosis factor- (TNF-) and interleukin 6 (IL-6). The results from CTRP3 Tg mice mirrored those from CTRP3 KO mice in most respects. This CTRP3/SIRT1/NF-{kappa}B relationship was also observed in the intestinal epithelial tissue of patients with active and inactive CD. CONCLUSIONSCTRP3 expression levels correlate negatively with intestinal inflammation in mouse colitis models and CD patients. CTRP3 attenuates intestinal inflammation via SIRT1/NF-{kappa}B signaling to suppress pro-inflammatory cytokines in mouse colitis models and patients with IBD. The manipulation of CTRP3 signaling, including through the use of SIRT1 agonists, may offer translational potential in the treatment of IBD. WHAT YOU NEED TO KNOWO_ST_ABSBACKGROUND AND CONTEXTC_ST_ABSAdipokine C1q/tumor necrosis factor-related protein 3 (CTRP3) is a novel adipokine with known non-intestinal anti-inflammatory effects. CTRP3 is reduced in the serum of patients with inflammatory bowel disease (IBD). However, little is known about whether and how CTRP3 influences intestinal inflammation in IBD. NEW FINDINGSCTRP3 mRNA and protein were detected in murine and human intestinal epithelial cells, as well as in murine intestinal smooth muscle cells and mesenteric fat. CTRP3 deletion was associated with more severe acute dextran sulfate sodium (DSS)-induced colitis, while CTRP3 overexpression was associated with less severe colitis. In both mice and humans, reduced CTRP3 levels correlated with reduced levels of the histone deacetylase Sirtuin 1 (SIRT1), resulting in the up-regulation of phosphorylated nuclear factor-kappa B (NF-{kappa}B) p65 and pro-inflammatory cytokine synthesis. LIMITATIONSThis study was performed using genetically modified mice and human tissue samples. An acute DSS-induced colitis model was used; additional mouse colitis models designed to mimic other aspects of IBD will be examined in future studies. The specific source of the secreted CTRP3 protein which influences intestinal inflammation is yet to be identified. The use of recombinant CTRP3 protein supplementation and SIRT1 agonists to mitigate intestinal inflammation also requires further study. IMPACTCTRP3 is a novel anti-inflammatory adipokine that attenuates intestinal inflammation in colitis mouse models and intestinal epithelial tissue of patients with IBD. CTRP3 attenuates intestinal inflammation by activating SIRT1, which suppresses the pro-inflammatory transcriptional activity of phosphorylated NF-{kappa}B p65. CTRP3 and SIRT1 agonists have potential as novel IBD drug targets.

pathology↗

bioRxiv2022

Genomic insights into metabolic flux in ruby-throated hummingbirds

Hummingbirds are very well adapted to sustain efficient and rapid metabolic shifts. They oxidize ingested nectar to directly fuel flight when foraging but have to switch to oxidizing stored lipids derived from ingested sugars during the night or long-distance migratory flights. Understanding how this organism moderates energy turnover is hampered by a lack of information regarding how relevant enzymes differ in sequence, expression, and regulation. To explore these questions, we generated a chromosome level de novo genome assembly of the ruby-throated hummingbird (A. colubris) using a combination of long and short read sequencing and scaffolding using other existing assemblies. We then used hybrid long and short-read RNA-sequencing for a comprehensive transcriptome assembly and annotation. Our genomic and transcriptomic data found positive selection of key metabolic genes in nectivorous avian species and a deletion of critical genes (GLUT4, GCK) involved in glucostasis in other vertebrates. We found expression of fructose-specific GLUT5 putatively in place of insulin-sensitive GLUT4, with predicted protein models suggesting affinity for both fructose and glucose. Alternative isoforms may even act to sequester fructose to preclude limitations from transport in metabolism. Finally, we identified differentially expressed genes from fasted and fed hummingbirds suggesting key pathways for the rapid metabolic switch hummingbirds undergo.

genomics↗

bioRxiv2021

Hepatocyte androgen receptor in females mediates androgen-induced hepatocellular glucose mishandling and systemic insulin resistance

Androgen excess is one of the most common endocrine disorders of reproductive-aged women, affecting up to 20% of this population. Women with elevated androgens often exhibit hyperinsulinemia and insulin resistance. The mechanisms of how elevated androgens affect metabolic function are not clear. Hyperandrogenemia in a dihydrotestosterone (DHT)-treated female mouse model induces whole body insulin resistance possibly through activation of the hepatic androgen receptor (AR). We investigated the role of hepatocyte AR in hyperandrogenemia-induced metabolic dysfunction by using several approaches to delete hepatic AR via animal-, cell-, and clinical-based methodologies. We conditionally disrupted hepatocyte AR in female mice developmentally (LivARKO) or acutely by tail vein injection of an adeno-associated virus with a liver-specific promoter for Cre expression in ARfl/fl mice (adLivARKO). We observed normal metabolic function in littermate female Control (ARfl/fl) and LivARKO (ARfl/fl; Cre+/-) mice. Following chronic DHT treatment, female Control mice treated with DHT (Con-DHT) developed impaired glucose tolerance, pyruvate tolerance, and insulin tolerance, not observed in LivARKO mice treated with DHT (LivARKO-DHT). Further, during an euglycemic hyperinsulinemic clamp, the glucose infusion rate was improved in LivARKO-DHT mice compared to Con-DHT mice. Liver from LivARKO, and primary hepatocytes derived from LivARKO, and adLivARKO mice were protected from DHT-induced insulin resistance and increased gluconeogenesis. These data support a paradigm in which elevated androgens in females disrupt metabolic function via hepatic AR and insulin sensitivity was restored by deletion of hepatic AR.

molecular biology↗

bioRxiv2021

PDE9 Inhibition Activates PPARa to Stimulate Mitochondrial Fat Metabolism and Reduce Cardiometabolic Syndrome

Central obesity with cardiometabolic syndrome (CMS) is a major global contributor to human disease, and effective therapies are needed. Here, we show inhibiting cyclic-GMP selective phosphodiesterase-9A (PDE9-I) suppresses established diet-induced obesity and CMS in ovariectomized female and male mice. PDE9-I reduces abdominal, hepatic, and myocardial fat accumulation, stimulates mitochondrial activity in brown and white fat, and improves CMS, without altering activity or food intake. PDE9 localizes to mitochondria, and its inhibition stimulates lipolysis and mitochondrial respiration coupled to PPAR-dependent gene regulation. PPAR upregulation is required for PDE9-I metabolic efficacy and is absent in non-ovariectomized females that also display no metabolic benefits from PDE9-I. The latter is compatible with estrogen receptor- altering PPAR chromatin binding identified by ChIPSeq. In humans with heart failure and preserved ejection fraction, myocardial expression of PPARA and its regulated genes is reduced versus control. These findings support testing PDE9-I to treat obesity/CMS in men and postmenopausal women. SummaryOral inhibition of phosphodiesterase type 9 stimulates mitochondrial fat metabolism and lipolysis, reducing central obesity without changing appetite

physiology↗

bioRxiv2020

Obesity alters Ace2 and Tmprss2 expression in lung, trachea, and esophagus in a sex-dependent manner: Implications for COVID-19

Obesity is a major risk factor for SARS-CoV-2 infection and COVID-19 severity. The underlying basis of this association is likely complex in nature. The host-cell receptor angiotensin converting enzyme 2 (ACE2) and the type II transmembrane serine protease (TMPRSS2) are important for viral cell entry. It is unclear whether obesity alters expression of Ace2 and Tmprss2 in the lower respiratory tract. Here, we show that: 1) Ace2 expression is elevated in the lung and trachea of diet-induced obese male mice and reduced in the esophagus of obese female mice relative to lean controls; 2) Tmprss2 expression is increased in the trachea of obese male mice but reduced in the lung and elevated in the trachea of obese female mice relative to lean controls; 3) in chow-fed lean mice, females have higher expression of Ace2 in the lung and esophagus as well as higher Tmprss2 expression in the lung but lower expression in the trachea compared to males; and 4) in diet-induced obese mice, males have higher expression of Ace2 in the trachea and higher expression of Tmprss2 in the lung compared to females, whereas females have higher expression of Tmprss2 in the trachea relative to males. Our data indicate diet- and sex-dependent modulation of Ace2 and Tmprss2 expression in the lower respiratory tract and esophagus. Given the high prevalence of obesity worldwide and a sex-biased mortality rate, we discuss the implications and relevance of our results for COVID-19.

physiology↗

bioRxiv2020

Glucose transporter expression and regulation following a fast in the ruby-throated hummingbird, Archilochus colubris.

Hummingbirds subsist almost exclusively on nectar sugar and face extreme challenges blood sugar regulation. Transmembrane sugar transport is mediated by facilitative glucose transporters (GLUTs) and the capacity for sugar transport is dependent on both the activity of GLUTs and their localisation to the plasma membrane (PM). In this study, we determined the relative protein abundance in whole-tissue (WT) homogenates and PM fractions via immunoblot using custom antibodies for GLUT1, GLUT2, GLUT3, and GLUT5 in flight muscle, heart, and, liver of ruby-throated hummingbirds (Archilochus colubris). GLUTs examined were detected in nearly all tissues tested. Hepatic GLUT1 was minimally present in WT homogenates and absent in PM fractions. GLUT5 was expressed in hummingbird flight muscles at levels comparable to that of their liver, consistent with the hypothesised uniquely high fructose-uptake and oxidation capacity of this tissue. To assess GLUT regulation, we fed ruby-throated hummingbirds 1M sucrose ad libitum for 24 hours followed by either 1 hour of fasting or continued ad libitum feeding until sampling. We measured relative GLUT abundance and concentrations of circulating sugars. Blood fructose concentration in fasted hummingbirds declined from [~]5mM to [~]0.18mM, while fructose-transporting PM GLUT2 and PM GLUT5 did not change in abundance. Blood glucose concentrations remained elevated in both fed and fasted hummingbirds, at [~]30mM, while glucose-transporting PM GLUT1 and PM GLUT3 in the flight muscle and liver, respectively, declined in fasted birds. Our results suggest that glucose uptake capacity is dynamically reduced in response to fasting, allowing for maintenance of elevated blood glucose levels, while fructose uptake capacity remains constitutively elevated promoting depletion of blood total fructose within the first hour of a fast. Summary statementHummingbird ingest nectar rich in glucose and fructose. When fasted, tissue capacity for circulating glucose import declines while remaining elevated for fructose. This may underlie maintenance of high blood glucose and rapid depletion of blood fructose.

zoology↗

bioRxiv2017

Single molecule, full-length transcript sequencing provides insight into the extreme metabolism of ruby-throated hummingbird Archilochus colubris

Hummingbirds can support their high metabolic rates exclusively by oxidizing ingested sugars, which is unsurprising given their sugar-rich nectar diet and use of energetically expensive hovering flight. However, they cannot rely on dietary sugars as a fuel during fasting periods, such as during the night, at first light, or when undertaking long-distance migratory flights, and must instead rely exclusively on onboard lipids. This metabolic flexibility is remarkable both in that the birds can switch between exclusive use of each fuel type within minutes and in that de novo lipogenesis from dietary sugar precursors is the principle way in which fat stores are built, sometimes at exceptionally high rates, such as during the few days prior to a migratory flight. The hummingbird hepatopancreas is the principle location of de novo lipogenesis and likely plays a key role in fuel selection, fuel switching, and glucose homeostasis. Yet understanding how this tissue, and the whole organism, achieves and moderates high rates of energy turnover is hampered by a fundamental lack of information regarding how genes coding for relevant enzymes differ in their sequence, expression, and regulation in these unique animals. To address this knowledge gap, we generated a de novo transcriptome of the hummingbird liver using PacBio full-length cDNA sequencing (Iso-Seq), yielding a total of 8.6Gb of sequencing data, or 2.6M reads from 4 different size fractions. We analyzed data using the SMRTAnalysis v3.1 Iso-Seq pipeline, including classification of reads and clustering of isoforms (ICE) followed by error-correction (Arrow). With COGENT, we clustered different isoforms into gene families to generate de novo gene contigs. We performed orthology analysis to identify closely related sequences between our transcriptome and other avian and human gene sets. We also aligned our transcriptome against the Calypte anna genome where possible. Finally, we closely examined homology of critical lipid metabolic genes between our transcriptome data and avian and human genomes. We confirmed high levels of sequence divergence within hummingbird lipogenic enzymes, suggesting a high probability of adaptive divergent function in the hepatic lipogenic pathways. Our results have leveraged cutting-edge technology and a novel bioinformatics pipeline to provide a compelling first direct look at the transcriptome of this incredible organism.

genomics↗