Patterns of Evolution in Graomys griseoflavus (Rodentia: Muridae): II. Reproductive Isolation between Cytotypes

Theiler, G.; Blanco, Antonio

doi:10.2307/1382683

Cited by 17 publications

(24 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rieseberg 2001, Capanna & Castiglia 2004. Moreover, several studies have supported the idea that Rb fusions cause reproductive isolation in a number of mammal species (Theiler & Blanco 1996, De Oliveira et al 2000, Rogatcheva et al 2000, Fernández-Donoso et al 2001, Jadwiszczak & Banaszek(Gü ndüz et al 2001, Sans-Fuentes et al 2007, and they can act as isolating barriers between populations. Meiotic non-disjunction (e.g.…”

Section: Introductionmentioning

confidence: 93%

Spermatogenesis in house mouse in a Robertsonian polymorphism zone

Sans-Fuentes¹,

García‐Valero²,

Ventura³

et al. 2010

Reproduction

View full text Add to dashboard Cite

Robertsonian (Rb) translocations can be important in speciation as a mechanism of postzygotic isolation between populations. Meiotic non-disjunction, gametogenic impairment, and association of impaired autosomal segments with sex chromosomes have been postulated as mechanisms responsible for reducing fertility in Rb mice. Quantitative histological studies needed to understand the role of Rb fusions in gametogenic impairment are scarce. Most research on Rb mice has analyzed meiotic non-disjunction of laboratory and wild-derived strains, which have complex or simple structural heterozygosity with large numbers of fusions. Using histological multilevel sampling, we examined spermatogenesis in mice from the Rb polymorphism area of Barcelona. We studied four chromosomal groups having: a) one Rb heterozygote fusion and 2nZ39, b) one Rb heterozygote fusion and 2nZ31, c) three Rb heterozygote fusions without monobrachial homology and with diploid number ranging from 2nZ29 to 2nZ37, and d) only Rb homozygote fusions with diploid number ranging from 2nZ28 to 2nZ30. Standard mice from the area surrounding the Rb zone were used as control. We analyzed morphological variables of the testes, relative frequency of stages in the seminiferous epithelium cycle, the 'round spermatids:primary spermatocytes' ratio, and other derived parameters. Our results reveal that structural homozygote mice and simple heterozygote mice having as few as one to three Rb fusions undergo greater germ cell death (GCD) than standard mice, suggesting that Rb fusions are related to increased GCD (in both the heterozygous and homozygous state) and may be the main cause of decreased gene flow between mice populations from this area.

show abstract

Section: Introductionmentioning

confidence: 93%

Spermatogenesis in house mouse in a Robertsonian polymorphism zone

Sans-Fuentes¹,

García‐Valero²,

Ventura³

et al. 2010

Reproduction

View full text Add to dashboard Cite

show abstract

“…It is most probable that one or more of species of large mammals from those families were the original hosts for A. neumanni and that all stages of this tick adapted to feed on cattle when the primeval fauna of wild large mammals started to be displaced by the introduced livestock 400 years ago. All evidences indicate that the surrogate cycle of A. neumanni is a successful one and, as proposed by Theiler and Blanco (1996) stated that the karyomorph 2n = 42 from Có rdoba is a separate sibling species from G. griseoflavus complex (2n = 38-36) Guglielmone et al (1990b), this species can actually survive with the presence of cattle only in the environment. Perhaps, the only evidence against the above statement is the low prevalence of larvae of A. neumanni, and the high values of SD and D that indicate a strongly skewed distribution with high infestation of few hosts.…”

Section: Discussionmentioning

confidence: 94%

The natural hosts for larvae and nymphs of Amblyomma neumanni and Amblyomma parvum (Acari: Ixodidae)

2006

View full text Add to dashboard Cite

Based on the hypothesis that birds and rodents are important hosts for subadults of the Neotropical Amblyomma neumanni and Amblyomma parvum ticks, a survey of these type of hosts was carried out from July 2004 to March 2006, in Quilino (A. parvum) and Dean Funes (A. neumanni), Córdoba province, Argentina. Additionally, monthly tick counts were performed on cattle and goats with occasional tick search in other domestic hosts. Records of questing height of subadult ticks on vegetation were also carried out monthly. Rodents (n = 123) and birds (n = 122) captured in Dean Funes showed no infestation with A. neumanni. Apart of few nymphs found on horses, all larvae and nymphs of A. neumanni were on cattle with a larval prevalence and mean number of 22.2%, and 7.7 +/- 22.52, respectively, and a prevalence of nymphs of 47.8% with a mean of 7.9 +/- 18.49. The average questing height of larvae and nymphs of A. neumanni was 23.5 +/- 17.1 cm and 30.7 +/- 26.7 cm, respectively. A total of 138 rodents and 130 birds were captured in Quilino but the Caviidae rodent Galea musteloides carried 99.3% of larvae and 99.8% of nymphs of A. parvum, and no immature stages were detected on cattle, goat or vegetation. Tick counts on G. musteloides (n = 74) showed a prevalence of 42% and a mean number of 9.9 +/- 24.83 for larvae, while nymphal infestation had a prevalence of 56.5% and a mean of 8.7 +/- 11.31. Cattle appear to be suitable hosts to sustain the complete cycle of A. neumanni in nature (adult ticks infest cattle too) and questing height of subadults indicates that they are expecting to feed on medium and large-sized mammals, such as cattle and other ungulates. At least in the study site, G. musteloides is the principal host for the survival strategy of A. parvum subadults; adult ticks are common on cattle and goats. These hosts are introduced in the Neotropics but A. neumanni was able to develop a surrogate cycle independent of native hosts while A. parvum still depends on probably primeval hosts to sustain their larvae and nymphs.

show abstract

“…The reproductive isolation was clearly asymmetric; there was no copula between males 2n ¼ 36-38 and females 2n ¼ 42, whereas the reciprocal crossings (females 2n ¼ 36-38 Â males 2n ¼ 42) produced viable sterile hybrid offspring with 39 or 40 chromosomes (Theiler and Blanco 1996a). Theiler and Blanco (1996b) also found reinforcement of this post-zygotic isolation by mechanisms involving olfactory discrimination during female estrus.…”

mentioning

confidence: 97%

“…Phylogenetic studies based on Cyt b and D-loop fragments of the mtDNA showed that animals with 2n ¼ 41 and 2n ¼ 42 form a separate clade from individuals with 2n ¼ 34-38, the latter being included in another well-supported group (Catanesi et al 2002 (Theiler 1997;Tiranti 1998;Theiler et al 1999) described 2n ¼ 42 cytotypes in individuals found in localities near Cruz del Eje, the site where the type specimens of Graomys centralis Thomas (1902) was obtained.…”

mentioning

confidence: 99%