Henkel, J. | Search bioRxiv

bioRxiv2021

Whole Genome Selective Sweeps Analysis in Pakistani Kamori Goat

Natural and artificial selection fix certain genomic regions of reduce heterozygosity which is an initial process in breed development. Primary goal of the current study is to identify these genomic selection signatures under positive selection and harbor genes in Pakistani Kamori goat breed. High throughput whole genome pooled-seq of Kamori (n = 12) and Bezoar (n = 8) was carried out. Raw fastq files were undergone quality checks, trimming and mapping process against ARS1 reference followed by calling variant allele frequencies. Selection sweeps were identified by applying pooled heterozygosity (Hp) and Tajimas D (TD) on Kamori while regions under divergent selection between Kamori & Bezoar were observed by Fixation Index (FST) analysis. Genome sequencing yielded 619,031,812 reads of which, 616,624,284 were successfully mapped. Total 98,574 autosomal selection signals were detected; 32,838 from Hp and 32,868 from each FST & TD statistics. Annotation of the regions with threshold (-ZHp [≥] 5, TD [≤] -2.72 & FST [≤] 0.09) detected 60 candidate genes. The top hits harbor Chr.1, 6, 8 & 21 having genes associated with body weight (GLIS3, ASTE1), coat color (DOCK8, MIPOL1) & body height (SLC25A21). Other significant windows harbor milk production, wool production, immunity, adaptation and reproduction trait related genes. Current finding highlighted the under-selection genomic regions of Kamori breed and likely to be associated with its vested traits and further useful in breed improvement, and may be also propagated to other undefined goat breeds by adopting targeted breeding policies to improve the genetic potential of this valued species.

genomics↗

bioRxiv2020

Dog color patterns explained by modular promoters of ancient canid origin

Distinctive color patterns in dogs are an integral component of canine diversity. Color pattern differences are thought to have arisen from mutation and artificial selection during and after domestication from wolves 1,2 but important gaps remain in understanding how these patterns evolved and are genetically controlled 3,4. In other mammals, variation at the ASIP gene controls both the temporal and spatial distribution of yellow and black pigments 3,5-7. Here we identify independent regulatory modules for ventral and hair cycle ASIP expression, and we characterize their action and evolutionary origin. Structural variants define multiple alleles for each regulatory module and are combined in different ways to explain five distinctive dog color patterns. Phylogenetic analysis reveals that the haplotype combination for one of these patterns is shared with arctic white wolves and that its hair cycle-specific module likely originated from an extinct canid that diverged from grey wolves more than 2 million years before present. Natural selection for a lighter coat during the Pleistocene provided the genetic framework for widespread color variation in dogs and wolves.

genetics↗