A Study of Hybridization Between Marmota baibacina and M. sibirica in Their Secondary Contact Zone in Mongolian Altai

Abstract

The role of hybridization as one of the factors of speciation in mammals has been underestimated for a long time, but now there is a lot of data on its impact in mammalian evolution. Hybridization of species often occurs in their secondary contact zones, which is a natural model for testing factors that ensure species integrity. Studies of hybrid zones are increasingly revealing the essential role of ecological and behavioral features both in initiating crossbreeding and in maintaining interspecific barriers. We studied the hybridization of two species of marmots Marmota baibacina and M. sibirica in the zone of sympatry in Mongolian Altai Mountains. We used a bioacoustic approach to determine the localization of individuals of different species and their cohabitation sites. Genetic typing with two diploid nuclear markers and one marker each of paternal and maternal lines was used to identify hybrids. Habitat preferences of marmots were studied to understand the conditions for the formation of heterospecific pairs. We found a high proportion of hybrid individuals in boulder screes where conditions for the formation of heterospecific pairs probably exist. Our data indicate the viability and fertility of F1 hybrids and their descendants. We hypothesize that the environmental preferences and behavioral features of both species of marmots are important factors that both create conditions for hybridization and limit hybrid dispersal.

Consequences of Hybridization in Mammals: A Systematic Review

“…In woodrat species ( Neotoma bryanti and Neotoma lepida ), a hybrid zone has been maintained as a result of sporadic cross-breeding between these species and hybrid fertility [ 196 ]. Among studies included in this literature review, hybrid zones have been described in mice ( Mus musculus musculus and Mus musculus domesticus ) [ 197 ], different woodrat species [ 195 , 196 , 198 , 199 , 200 ], marmots [ 201 ], primates [ 181 ], artiodactyles [ 157 , 202 ], Diprotodontia [ 203 , 204 ] and carnivores [ 138 , 205 ].…”

Surrounded by Kindred: Spermophilus major Hybridization with Other Spermophilus Species in Space and Time

“…To assess the effect of hybridization on the Spermophilus nuclear genome, we assessed the genetic markers of the fragments of the male-specific histocompatibility antigen SmcY , containing intron 8 and partial cds [ 53 ], and biglycan ( BGN ) [ 66 ], localized on the Y and X chromosomes, respectively. Sequences of autosomal genes were also assessed: intron 13 of the breakpoint cluster region ( i13BCR ) [ 25 ], mechano growth factor ( MGF ), beta-acid glucosidase ( GBA ) [ 66 ], protein kinase C, iota ( PRKCI ) [ 67 ], thyrotropin ( THY ) [ 68 ], proto-oncogene c-myc ( c-myc ) [ 69 ], and the ID repeat in intron 6 of transformation-related protein 53 ( i6p53 ) [ 52 ]. For this purpose, the nucleotide sequences of all the previously mentioned markers, except for i6p53 , were sequenced for 20 randomly selected samples of S. major from the entire range and from 2 (for S. erythrogenys ) to 43 samples of the other species.…”

“…Hybridization in mammals is no longer considered a rare phenomenon [ 24 , 25 , 26 , 27 ]. Meanwhile, its influence on the evolutionary history on each particular species is not the same.…”

Putative hybrids between Indian giant squirrels (Ratufa indica) and grizzled giant squirrels (Ratufa macroura): a case study from the Western Ghats, India.

“…Interspeci c hybridization has been reported in several vertebrate groups across the world. Natural hybridization often occurs when previously allopatric species or populations eventually come into secondary contact, leading to the gene ow between them (Harrison and Larson, 2014;Brandler et al, 2021). Even though hybridization frequently results in non-viable or sterile offspring, examples of evolutionarily successful hybrid populations have been documented in many taxonomic groups (Burke and Arnold, 2001).…”