Genome-wide analysis of positively selected genes in seasonal and non-seasonal breeding species

Adaptation in the Alleyways: Candidate Genes Under Potential Selection in Urban Coyotes

In the context of evolutionary time, cities are an extremely recent development. Although our understanding of how urbanization alters ecosystems is well developed, empirical work examining the consequences of urbanization on adaptive evolution remains limited. To facilitate future work, we offer candidate genes for one of the most prominent urban carnivores across North America. The coyote (Canis latrans) is a highly adaptable carnivore distributed throughout urban and nonurban regions in North America. As such, the coyote can serve as a blueprint for understanding the various pathways by which urbanization can influence the genomes of wildlife via comparisons along urban-rural gradients, as well as between metropolitan areas. Given the close evolutionary relationship between coyotes and domestic dogs, we leverage the well-annotated dog genome and highly conserved mammalian genes from model species to outline how urbanization may alter coyote genotypes and shape coyote phenotypes. We identify variables that may alter selection pressure for urban coyotes and offer suggestions of candidate genes to explore. Specifically, we focus on pathways related to diet, health, behavior, cognition, and reproduction. In a rapidly urbanizing world, understanding how species cope and adapt to anthropogenic change can facilitate the persistence of, and coexistence with, these species.

High-density genotyping reveals signatures of selection related to acclimation and economically important traits in 15 local sheep breeds from Russia

Background

Domestication and centuries of selective breeding have changed genomes of sheep breeds to respond to environmental challenges and human needs. The genomes of local breeds, therefore, are valuable sources of genomic variants to be used to understand mechanisms of response to adaptation and artificial selection. As a step toward this we performed a high-density genotyping and comprehensive scans for signatures of selection in the genomes from 15 local sheep breeds reared across Russia.

Results

Results demonstrated that the genomes of Russian sheep breeds contain multiple regions under putative selection. More than 50% of these regions matched with intervals identified in previous scans for selective sweeps in sheep genomes. These regions contain well-known candidate genes related to morphology, adaptation, and domestication (e.g., KITLG, KIT, MITF, and MC1R), wool quality and quantity (e.g., DSG@, DSC@, and KRT@), growth and feed intake (e.g., HOXA@, HOXC@, LCORL, NCAPG, LAP3, and CCSER1), reproduction (e.g., CMTM6, HTRA1, GNAQ, UBQLN1, and IFT88), and milk-related traits (e.g., ABCG2, SPP1, ACSS1, and ACSS2). In addition, multiple genes that are putatively related to environmental adaptations were top-ranked in selected intervals (e.g., EGFR, HSPH1, NMUR1, EDNRB, PRL, TSHR, and ADAMTS5). Moreover, we observed that multiple key genes involved in human hereditary sensory and autonomic neuropathies, and genetic disorders accompanied with an inability to feel pain and environmental temperatures, were top-ranked in multiple or individual sheep breeds from Russia pointing to a possible mechanism of adaptation to harsh climatic conditions.

Conclusions

Our work represents the first comprehensive scan for signatures of selection in genomes of local sheep breeds from the Russian Federation of both European and Asian origins. We confirmed that the genomes of Russian sheep contain previously identified signatures of selection, demonstrating the robustness of our integrative approach. Multiple novel signatures of selection were found near genes which could be related to adaptation to the harsh environments of Russia. Our study forms a basis for future work on using Russian sheep genomes to spot specific genetic variants or haplotypes to be used in efforts on developing next-generation highly productive breeds, better suited to diverse Eurasian environments.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5537-0) contains supplementary material, which is available to authorized users.

Comparative transcriptome analysis reveals potential evolutionary differences in adaptation of temperature and body shape among four Percidae species

Considering the divergent temperature habitats and morphological traits of four Percidae species: yellow perch (Perca flavescens), Eurasian perch (Perca fluviatilis), pike perch (Sander lucioperca), and ruffe (Gymnocephalus cernua), we stepped into the transcriptome level to discover genes and mechanisms that drive adaptation to different temperature environments and evolution in body shape. Based on 93,566 to 181,246 annotated unigenes of the four species, we identified 1,117 one-to-one orthologous genes and subsequently constructed the phylogenetic trees that are consistent with previous studies. Together with the tree, the ratios of nonsynonymous to synonymous substitutions presented decreased evolutionary rates from the D. rerio branch to the sub-branch clustered by P. flavescens and P. fluviatilis. The specific 93 fast-evolving genes and 57 positively selected genes in P. flavescens, compared with 22 shared fast-evolving genes among P. fluviatilis, G. cernua, and S. lucioperca, showed an intrinsic foundation that ensure its adaptation to the warmer Great Lakes and farther south, especially in functional terms like “Cul4-RING E3 ubiquitin ligase complex.” Meanwhile, the specific 78 fast-evolving genes and 41 positively selected genes in S. lucioperca drew a clear picture of how it evolved to a large and elongated body with camera-type eyes and muscle strength so that it could occupy the highest position in the food web. Overall, our results uncover genetic basis that support evolutionary adaptation of temperature and body shape in four Percid species, and could furthermore assist studies on environmental adaptation in fishes.

Natural selection shaped the rise and fall of passenger pigeon genomic diversity

The extinct passenger pigeon was once the most abundant bird in North America, and possibly the world. Although theory predicts that large populations will be more genetically diverse, passenger pigeon genetic diversity was surprisingly low. To investigate this disconnect, we analyzed 41 mitochondrial and 4 nuclear genomes from passenger pigeons and 2 genomes from band-tailed pigeons, which are passenger pigeons' closest living relatives. Passenger pigeons' large population size appears to have allowed for faster adaptive evolution and removal of harmful mutations, driving a huge loss in their neutral genetic diversity. These results demonstrate the effect that selection can have on a vertebrate genome and contradict results that suggested that population instability contributed to this species's surprisingly rapid extinction.

DNAH1 gene mutations and their potential association with dysplasia of the sperm fibrous sheath and infertility in the Han Chinese population

OBJECTIVE

To investigate dynein, axonemal, heavy chain 1 (DNAH1) gene mutations that may be associated with dysplasia of the sperm fibrous sheath (DFS) and infertility in the Han Chinese population.

DESIGN

Dysfunction of DNAH1 is known to cause multiple morphologic abnormalities of the flagella (MMAF), DFS, and infertility. Whole-exome sequencing was performed in DFS subjects and the healthy control subjects.

SETTING

Not applicable.

PATIENT(S)

Twenty-one patients of Han ethnicity with primary infertility and diagnosed with asthenozoospermia and MMAF, but without primary ciliary dyskinesia. Fifty healthy men with normal fertility served as control subjects.

MAIN OUTCOME MEASURE(S)

Whole-exome sequencing, polymerase chain reaction and sequencing, pedigree analysis, Western blotting, and immunofluorescence assay.

INTERVENTIONS(S)

None.

RESULT(S)

A total of 17 mutations in the DNAH1 gene were identified in 12 of the 21 patients. These included one homozygous mutation at the splice site and 16 complex heterozygous mutations at the splice sites and exons. These mutations may cause deletion, replacement of amino acids in the peptide, or introduction of a stop codon in the coding sequence according to bioinformatic prediction. Of note, 52430998CCT>C deletion at exon 73, which may result in c.11726_11727del:p.P3909fs, was found in six patients, which suggests that this mutation may be an etiologic factor for MMAF. Although these DNAH1 gene mutations were found in Exome Aggregation Consortium (ExAC) databases, none were found in the Han healthy control subjects. The expression of DNAH1 protein in the sperm of patient P10, with 52409336C>T in exon 45 and 52430998CCT>C in exon 73 mutations, and patient P12, with 52402755A>G in exon 37 and 52428484G>T in exon 67 mutations, was missing or very weak compared with the sperm of healthy control subjects. The peptide phenotypes of 52409336C>T, 52402755A>G, and 52428484G>T were R2356W, nonsense, and E3544X, respectively. The sperm tails were short or coiled in P10 and P12 compared with healthy control subjects. Pedigree analysis supported the notion that the combination of DNAH1 gene mutations 52430998CCT>C and 52409336C>T and 52428484G>T alone were associated with MMAF.

CONCLUSION(S)

These DNAH1 gene mutations may be associated with DFS and infertility in the Han population.