Biology subjects

Grogan, K. E.

Publications and source records attributed to Grogan, K. E..

4 recordsLinked to original sources

bioRxiv2021

The power of peer networking for improving STEM faculty job applications: a successful pilot program

In order to successfully obtain a faculty position, postdoctoral fellows or postdocs, must submit an application which requires considerable time and effort to produce. These job applications are often reviewed by mentors and colleagues, but rarely are postdocs offered the opportunity to solicit feedback multiple times from reviewers with the same breadth of expertise often found on an academic search committee. To address this gap, this manuscript describes an international peer reviewing program for small groups of postdocs with a broad range of expertise to reciprocally and iteratively provide feedback to each other on their application materials. Over 145 postdocs have participated, often multiple times, over three years. A survey of participants in this program revealed that nearly all participants would recommend participation in such a program to other faculty applicants. Furthermore, this program was more likely to attract participants who struggled to find mentoring and support elsewhere, either because they changed fields or because of their identity as a woman or member of an underrepresented population in STEM. Participation in programs like this one could provide early career academics like postdocs with a diverse and supportive community of peer mentors during the difficult search for a faculty position. Such psychosocial support and encouragement has been shown to prevent attrition of individuals from these populations and programs like this one target the largest leak in the pipeline, that of postdoc to faculty. Implementation of similar peer reviewing programs by universities or professional scientific societies could provide a valuable mechanism of support and increased chances of success for early-career academics in their search for independence.

scientific communication and education↗

bioRxiv2020

Evolutionary genomic patterns of recent natural selection on loci associated with sexually differentiated human body size and shape phenotypes

Levels of sex differences for human body size and shape phenotypes are hypothesized to have adaptively reduced following the agricultural transition as part of an evolutionary response to relatively more equal divisions of labor and new technology adoption. In this study, we tested this hypothesis by studying genetic variants associated with five sexually differentiated human phenotypes: height, body mass, hip circumference, body fat percentage, and waist circumference. We first analyzed genome-wide association (GWAS) results for UK Biobank individuals ([~]197,000 females and [~]167,000 males) to identify a total of 119,023 single nucleotide polymorphisms (SNPs) significantly associated with at least one of the studied phenotypes in females, males, or both sexes (P<5x10-8). From these loci we then identified 3,016 SNPs (2.5%) with significant differences in the strength of association between the female- and male-specific GWAS results at a low false-discovery rate (FDR<0.001). Genes with known roles in sexual differentiation are significantly enriched for co-localization with one or more of these SNPs versus SNPs associated with the phenotypes generally but not with sex differences (2.93-fold enrichment; permutation test; P=0.0041). We also confirmed that the identified variants are disproportionately associated with greater phenotype effect sizes in the sex with the stronger association value. We then used the singleton density score statistic, which quantifies recent (within the last [~]3,000 years; post-agriculture adoption in Britain) changes in the frequencies of alleles underlying polygenic traits, to identify a signature of recent positive selection on alleles associated with greater body fat percentage in females (permutation test; P=0.0038; FDR=0.0380), directionally opposite to that predicted by the sex differentiation reduction hypothesis. Otherwise, we found no evidence of positive selection for sex difference-associated alleles for any other trait. Overall, our results challenge the longstanding hypothesis that sex differences adaptively decreased following subsistence transitions from hunting and gathering to agriculture. Author SummaryThere is uncertainty regarding the evolutionary history of human sex differences for quantitative body size and shape phenotypes. In this study we identified thousands of genetic loci that differentially impact body size and shape trait variation between females and males using a large sample of UK Biobank individuals. After confirming the biological plausibility of these loci, we used a population genomics approach to study the recent (over the past 3,000 years) evolutionary histories of these loci in this population. We observed significant increases in the frequencies of alleles associated with greater body fat percentage in females. This result is contradictory to longstanding hypotheses that sex differences have adaptively decreased following subsistence transitions from hunting and gathering to agriculture.

evolutionary biology↗

bioRxiv2020

A behavioral polymorphism caused by a single gene inside a supergene

Behavioral evolution relies on genetic changes, yet few social behaviors can be traced to specific genetic sequences in vertebrates. Here, we show experimental evidence that differentiation of a single gene has contributed to divergent behavioral phenotypes in the white-throated sparrow, a common North American songbird. In this species, one of two alleles of ESR1, encoding estrogen receptor (ER), has been captured inside a differentiating supergene that segregates with an aggressive phenotype, such that ESR1 expression predicts aggression. Here, we show that the aggressive phenotype associated with the supergene is prevented by ESR1 knockdown in a single brain region. Next, we show that in a free-living population, aggression is predicted by allelic imbalance favoring the supergene allele. Cis-regulatory variation between the two alleles affects transcription factor binding sites, DNA methylation, and rates of transcription. This work provides a rare illustration of how genotypic divergence has led to behavioral phenotypic divergence in a vertebrate.

neuroscience↗

bioRxiv2019

Expression of oxytocin receptors in the zebra finch brain during vocal development

Juvenile male zebra finches memorize and learn to sing the song of a male caregiver, or \"tutor\", during a complex vocal learning process. Juveniles are highly motivated to interact socially with their tutor, and these interactions are required for effective vocal learning. It is currently unknown what neurological mechanisms underlie attraction to tutors, but social motivation and affiliation in this and other species may be mediated by oxytocin and related nonapeptides. Here, we used qPCR to quantify expression of oxytocin receptor (OTR) mRNA in the lateral septum, auditory forebrain, and regions of the song control system in zebra finches throughout post-hatch development and vocal learning. We found that zebra finches express OTR mRNA in these regions from post-hatch day 5 to adulthood, encompassing the entire period of auditory and sensorimotor learning. We also mapped the binding of 125I-ornithine vasotocin, an oxytocin receptor antagonist that binds to oxytocin receptors in songbird brain, to understand the neuroanatomical distribution of oxytocin-like action during vocal development. This study provides the groundwork for the use of zebra finches as a model for understanding the mechanisms underlying social motivation and its role in vocal development.

neuroscience↗