Biology subjects

Abt, K.

Publications and source records attributed to Abt, K..

3 recordsLinked to original sources

bioRxiv2026

Intermittent exposure to high ambient heat during the second half of gestation in mice causes mild alterations of reproductive endpoints in male embryos

Periods of elevated ambient temperature challenge the bodys ability to maintain internal homeostasis, and heat stress poses particular risks during pregnancy. Epidemiological studies associate gestational heat exposure with higher rates of congenital anomalies such as hypospadias, yet the direct link between gestational heat exposure and reproductive anomalies remains unknown. In this study, we examined the effects of intermittent heat exposure on reproductive development in male mouse offspring. Pregnant dams either remained at constant temperature of 22{degrees}C (control) or were exposed to 38{degrees}C for 2 hours daily (experimental) from embryonic day (E)10 to E18, modeling intermittent heat exposure during mid-to-late gestation. Embryos were collected at E18 for analysis. While heat exposure did not affect pregnancy outcomes, including placental development, litter size, sex ratio, or fetal growth, male embryos exhibited significantly reduced anogenital distance and increased hypospadias scores, which are both markers of disrupted androgen signaling. Despite these phenotypic changes, expression of genes involved in androgen synthesis in the fetal testis, as well as gene expression in external genitalia, remained unchanged. Instead, transcriptomic analysis revealed significant alterations in testicular pathways related to RNA splicing and mRNA processing. Together, these findings reveal that maternal heat stress disrupts reproductive development of male offspring, with altered gene regulatory processes being a potential driver.

developmental biology↗

bioRxiv2022

TAF4b Transcriptional Regulation During Cellular Quiescence of Developing Prospermatogonia

Prospermatogonia (ProSpg) link the embryonic development of male primordial germ cells to the healthy establishment of postnatal spermatogonia and long-term mammalian spermatogenesis. While these spermatogenic precursor cells undergo the characteristic transitions of cycling and quiescence, the transcriptional events underlying these developmental hallmarks remain unknown. Here we investigated the expression and function of TAF4b in the timely development of mouse ProSpg using an integration of gene expression profiling and chromatin mapping. We find that Taf4b mRNA expression is elevated during the transition of M-to-T1 ProSpg and Taf4b-deficient ProSpg are delayed in their entry into quiescence. Gene ontology, protein network analysis, and chromatin mapping demonstrate that TAF4b is both a direct and indirect regulator of cell cycle-related gene expression programs during ProSpg quiescence. By comparing the transcriptome changes in male and female Taf4b-deficient embryonic germ cells, we revealed that TAF4b promotes sex-independent and -dependent gene expression pathways, highlighting its unique and critical role in the fertility of both sexes.

genetics↗

bioRxiv2018

Reducing tau ameliorates behavioural and transcriptional deficits in a novel model of Alzheimer’s disease

SummaryOne of the key knowledge gaps blocking development of effective therapeutics for Alzheimers disease (AD) is the lack of understanding of how amyloid beta (A{beta}) and tau cooperate in causing disease phenotypes. Within a mouse tau deficient background, we probed the molecular, cellular and behavioural disruption triggered by wild-type human taus influence on human A{beta}-induced pathology. We find that A{beta} and tau work cooperatively to cause a hyperactivity phenotype and to cause downregulation of gene transcription including many involved in synaptic function. In both our mouse model and in human post-mortem tissue, we observe accumulation of pathological tau in synapses, supporting the potential importance of synaptic tau. Importantly, tau depletion in the mice, initiated after behavioural deficits emerge, was found to correct behavioural deficits, reduce synaptic tau levels, and substantially reverse transcriptional perturbations, suggesting that lowering tau levels, particularly at the synapse, may be beneficial in AD.\n\nHighlights- Expression of human familial Alzheimers associated mutant amyloid precursor protein and presenillin 1 with wild-type human tau in the absence of endogenous tau in a novel MAPT-AD mouse model results in behavioural deficits and downregulation of genes involved in synaptic function.\n- Tau is present in pre and postsynaptic terminals in MAPT-AD mice and human AD brain. In mice, lowering synaptic tau levels was associated with improved cognition and recovered gene expression.\n- These data suggest that A{beta} and tau act cooperatively in impairing synaptic function and that lowering tau at synapses could be a beneficial therapeutic approach in AD.

neuroscience↗