Genetic variation of major histocompatibility complex genes in the endangered red-crowned crane

Abstract

Populations that have drastically decreased in the past often have low genetic variation, which may increase the risk of extinction. The genes of major histocompatibility complex (MHC) play an important role in the adaptive immune response of jawed vertebrates. Maintenance of adaptive genetic diversity such as that of MHC genes is important for wildlife conservation. Here, we determined genotypes of exon 3 of MHC class IA genes (MHCIA) and exon 2 of MHC class IIB genes (MHCIIB) to evaluate genetic variation of the endangered red-crowned crane population on Hokkaido Island, Japan, which experienced severe population decline in the past. We identified 16 and 6 alleles of MHCIA and MHCIIB, respectively, from 152 individuals. We found evidence of a positive selection at the antigen-binding sites in MHCIA exon 3 and MHCIIB exon 2. The phylogenetic analyses indicated evidence of trans-species polymorphism among the crane MHC genes. The genetic variability in both classes of MHC genes at the population level was low. No geographic structure was found based on the genetic diversity of microsatellite and MHC genes. Our study provides useful data for the optimal management of the red-crowned crane population in Hokkaido and can contribute to future studies on MHC genes of the continental populations of the red-crowned crane and other crane species.

High MHC gene copy number maintains diversity despite homozygosity in a Critically Endangered single‐island endemic bird, but no evidence of MHC‐based mate choice

“…This species only has 10 alleles over at least four loci (Richardson & Westerdahl, 2003), although analyses with high throughput sequencing might reveal somewhat higher diversity. Among bottlenecked non‐passerines, the white‐tailed eagle Haliaeetus albicilla (1,000 pairs in the core distribution in Central and Northern Europe during the 1970s) has only 10 MHC‐I alleles over at least three loci (Minias, Pikus, & Anderwald, 2019), the Vulnerable Chinese egret Egretta eulophotes (declining population of 2,600–3,400 individuals) has 14 alleles but shows little polymorphism in presumably only two loci (Chiang et al., 2017), and 16 alleles over six loci were found in the Endangered red‐crowned crane Grus japonica (declining population of 1,830 individuals) (Akiyama et al., 2017). However, it is important to note that, in general, non‐passerine birds have fewer MHC loci (Minias, Pikus, Whittingham, et al, 2019).…”

“…Europe during the 1970s) has only 10 MHC-I alleles over at least three loci (Minias, Pikus, & Anderwald, 2019), the Vulnerable Chinese egret Egretta eulophotes (declining population of 2,600-3,400 individuals) has 14 alleles but shows little polymorphism in presumably only two loci (Chiang et al, 2017), and 16 alleles over six loci were found in the Endangered red-crowned crane Grus japonica (declining population of 1,830 individuals) (Akiyama et al, 2017). However, it is important to note that, in general, non-passerine birds have fewer MHC loci (Minias, Pikus, Whittingham, et al, 2019).…”

Genetic Diversity and Relatedness among Captive African Painted Dogs in North America

“…Endangered species research has increasingly included assessments of variation at the MHC loci due to the adaptive role that the MHC plays in the immune response to pathogens [34][35][36][37][38][39]. The canid MHC, known as the dog leucocyte antigen (DLA) loci, includes four tightly linked functional nuclear genes that together encode the α and β chains of MHC class II molecules [40].…”

Blood Transcriptome Analysis reveals Age-associated changes in Expression Profile of Immune-Related Gene in Golden snub-nosed Monkey (Rhinopithecus roxellana)

“…Whereas, apoptotic cells can secrete elongation factor 1-alpha 1 and other elongation factors to induce autoimmune response during cancer and help kill cancer cells [36]. MHC class-I gene and MHC class-II gene play a pivotal role by presenting peptide antigens and leading to CD4 + T cell-dependent cellular and humoral immune responses [37,38]. The up-regulated expression of these genes implied that the enhancement of immunity in adult group compared to the young group.…”