Biology subjects

Bauer, H.

Publications and source records attributed to Bauer, H..

3 recordsLinked to original sources

bioRxiv2025

Targeted sex ratio distortion in the mouse

In animal breeding, female or male progeny is preferred depending on the use of the animals. Especially in livestock, offspring with undesired sex is of low economic value and often culled. Here we achieve targeted sex ratio distortion in the mouse, leveraging components of a selfish supergene, the t-haplotype. Utilizing its central element, the t-responder, we generate a highly "selfless" genetic element disabling transgenic sperm. When integrated on the X or Y chromosome it results in a high prevalence of non-transgenic offspring of the desired sex. Our strategy overcomes key limitations of existing strategies, including compromised animal health, reduced fertility, and fully transgenic breeding stocks, which might foster acceptance of its application to livestock. The efficacy of our approach marks a groundbreaking advancement in animal breeding. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=130 HEIGHT=200 SRC="FIGDIR/small/660540v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@1b11374org.highwire.dtl.DTLVardef@742ec5org.highwire.dtl.DTLVardef@1aaafc0org.highwire.dtl.DTLVardef@f87dac_HPS_FORMAT_FIGEXP M_FIG C_FIG Transgene integration on X or Y chromosome affects the motility of transgenic sperm resulting in a strong sex-bias towards non-transgenic/wildtype offspring. Application to livestock can reduce unwanted progeny and transform farm animal breeding.

genetics↗

bioRxiv2025

Acquisition of ampliconic sequences marks a selfish mouse t-haplotype

Mendelian genetics posits equal transmission of alleles, but selfish alleles can bias the transmission of large genomic regions or entire chromosomes1-4. One long-standing question is how transmission bias evolves to encompass large genomic regions. Mus musculus (house mouse) t-haplotypes exhibit up to 99% transmission bias from heterozygous males5-14 and harbor selfish alleles9-14 genetically linked to large inversions spanning the proximal half of chromosome 1715-20. Here, by generating a high-quality, single-haplotype assembly of a t- haplotype, we reveal the evolution of eight large amplicons with known11,13,21 and candidate selfish alleles as a distinct genetic feature. Three amplicons are conserved in closely related Mus species, and two have known selfish alleles in the oldest inversion, implicating amplicons and an inversion drove the origins of a selfish chromosome 17 [~]3MYA. The remaining t- haplotype amplicons harbor gene families expressed predominantly in haploid spermatids, newly acquired retrogenes, and the most differentially expressed genes in wild-type/t-haplotype spermatids. Targeted deletion of a [~]1.8Mb amplicon with candidate selfish alleles on the t- haplotype reduces selfish transmission in heterozygous males by 3%. Notably, the evolution of selfish allele-containing amplicons and inversions on the t-haplotype parallels mammalian sex chromosome evolution as signatures of selfish transmission. We propose amplicon acquisition and large inversions initiate evolutionary arms races between selfish haplotypes and serve as genome-wide signatures of selfish transmission.

genetics↗

bioRxiv2019

Whole genome sequencing and the application of a SNP panel reveal primary evolutionary lineages and genomic diversity in the lion (Panthera leo)

BackgroundPrevious phylogeographic studies of the lion (Panthera leo) have improved our insight into the distribution of genetic variation, as well as a revised taxonomy which now recognizes a northern (Panthera leo leo) and a southern (Panthera leo melanochaita) subspecies. However, existing whole range phylogeographic studies on lions either consist of very limited numbers of samples, or are focused on mitochondrial DNA and/or a limited set of microsatellites. The geographic extent of genetic lineages and their phylogenetic relationships remain uncertain, clouded by massive sampling gaps, sex-biased dispersal and incomplete lineage sorting. ResultsIn this study we present results of low depth whole genome sequencing and subsequent variant calling in ten lions sampled throughout the geographic range, resulting in the discovery of >150,000 Single Nucleotide Polymorphisms (SNPs). Phylogenetic analyses revealed the same basal split between northern and southern populations as well as four population clusters on a more local scale. Further, we designed a SNP panel, including 125 autosomal and 14 mitochondrial SNPs, which was tested on >200 lions from across their range. Results allow us to assign individuals to one of these four major clades (West & Central Africa, India, East Africa, or Southern Africa) and delineate these clades in more detail. ConclusionsThe results presented here, particularly the validated SNP panel, have important applications, not only for studying populations on a local geographic scale, but also for tracing samples of unknown origin for forensic purposes, and for guiding conservation management of ex situ populations. Thus, these genomic resources not only contribute to our understanding of the evolutionary history of the lion, but may also play a crucial role in conservation efforts aimed at protecting the species in its full diversity.

evolutionary biology↗