RIBOSOMAL-DNA, MITOCHONDRIAL-DNA, CHROMOSOMAL, AND ALLOZYMIC STUDIES ON A CONTACT ZONE IN THE POCKET GOPHER, GEOMYS

摘要: We studied 75 individuals of the Plains pocket gopher, Geomys bursarius, from eastern New Mexico, where subspecies major and knoxjonesi hybridize. Each individual was examined for chromosome number, ribosomal DNA, mitochondrial three protein systems which reference parental populations were fixed alternative alleles. Twenty indistinguishable major, 14 knoxjonesi, 41 had genotypes composed combinations character states that distinguish two types. The types appear to represent discrete genetic entities have restricted introgression across a narrow hybrid zone (width approximately 3 km, using 20/80 criterion). Parental overlap in geographic distribution near center zone, changes DNA five nuclear markers are concordant zone. It is probable there premating isolation between males females. frequencies with certain genotypic within our sample imply differential reproductive success genotypes. propose F1 's highly heterozygous sterile females less fertile than These postmating factors, along one reciprocal crosses, probably account restriction gene flow contact structure can be explained by "dynamic equilibrium" model.