Spermatogenesis in a Male Hinny: Histological and Cytological Studies

Trujillo, José M.; Ohno, Susumu; Jardine, John H.; Atkins, N. B.

doi:10.1093/oxfordjournals.jhered.a107940

Cited by 14 publications

(17 citation statements)

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“…1964;Trujillo et al, 1969;Chandley et al, 1974). It is probable that sperm density is just too low in male hybrids to allow a conception to take place.…”

Section: Discussionmentioning

confidence: 99%

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A fertile mule and hinny in China

Rong

Chandley²,

Song³

et al. 1988

Cytogenet Genome Res

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Anecdotal reports of fertility in female mules (jack donkey × mare) and hinnies (stallion × jenny donkey) have appeared in the literature over the years, but scientists have generally regarded them with scepticism. The fact that some of these hybrids can come into estrous and ovulate makes fertility conceivable, given that opportunity for mating arises. In China, where mules are bred extensively for work on the farms, a fertile female mule and a fertile female hinny have now been verified by chromosomal investigation. Each had mated with a donkey and produced a filly foal. The foals show unique hybrid karyotypes different from the mule’s or hinny’s and different from each other’s. The studies make it clear that mule and hinny fertility, at least for the female hybrid, is a real possibility.

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“…1964;Trujillo et al, 1969;Chandley et al, 1974). It is probable that sperm density is just too low in male hybrids to allow a conception to take place.…”

Section: Discussionmentioning

confidence: 99%

“…Synaptic irregularities are a usual feature of prophase chromosomes in spermatocytes (Makino, 1955;Trujillo et al. 1969;Chandley et al.…”

Section: Discussionmentioning

confidence: 99%

A fertile mule and hinny in China

Rong

Chandley²,

Song³

et al. 1988

Cytogenet Genome Res

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show abstract

“…Connective tissue elements and a few groups of mature Leydig cells are also present in the interstitial spaces between the seminiferous tubules, while there is intertubular fibrosis in the epididymides, as well as in the vas deferens (Jauregui and Monter 1977). Cytogenetic (Marquez, Kofman and Hernandez 1974 ; Chandley et a/ 1974), histological and ultrastructural (Jauregui and Monter 1977) studies on the mule testis have demonstrated a 'blockage' of spermatogenesis at the pachytene stage of meiosis, although a few mature spermatozoa have been reported in the semen of some male mules and hinnies (Bratanov, Dikov and Dokov 1964;Trujillo, Ohno, Jardine and Atkins 1969).…”

Section: Discussionmentioning

confidence: 99%

Spontaneous seminoma in a mule

Galofaro

Guardo

1986

Equine Veterinary Journal

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“…If fertile balanced gametes capable of siring offspring occur in hybrids between species with different chromosome numbers (e.g. in mules and hinnies: Trujillo et al, 1969;Chandley et al, 1974, Rong et al, 1988Zong & Fan, 1989), it is generally not possible to predict accurately the karyotype of the backcross progeny for two reasons. First, balanced gametes may arise due to several meiotic configurations (Yang et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Chromosome inheritance and reproductive barriers in backcrosses between two hybridizing Viviparus snail species

Sbilordo

Martin

Ribi³

2012

Journal of Molluscan Studies

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Hybridization must be followed by repeated backcrossing of the subsequent hybrid generations to the parental species for gene exchange between species to occur. Due to meiotic failures, first-generation hybrids of some species produce unreduced gametes. Their progeny in backcrosses with a diploid parental species are polyploid and functionally sterile. Polyploidy of the backcross generation may therefore act as an instantaneous barrier to gene flow between hybrids and the parental species. Here we determined chromosome inheritance in backcrosses of two hybridizing freshwater caenogastropod snail species to assess whether gene introgression is inhibited in the first backcross generation. Viviparus ater and V. contectus intermate in nature and produce viable F1 hybrid progeny, although offspring sex ratio is strongly male biased. Despite the different chromosome numbers of the two parental species (V. ater, 2n ¼ 18; V. contectus, 2n ¼ 14), the F1 hybrids are able to reproduce. Allozyme data from natural populations are compatible with gene exchange between the two species, although there is also evidence suggesting that some alleles may be shared because of common ancestry. Our study revealed that all viable backcross progeny were homoploid as they inherited between seven and nine chromosomes from the hybrid father. The siring success of the karyotypically different hybrid sperm was skewed against one sperm karyotype depending on the non-hybrid mother in the cross. In backcross broods of V. ater females, the observed distribution of the karyotypes conformed with an assumption of random segregation of two unpaired chromosomes at meiosis in hybrid males. In contrast, when backcrossing hybrid males to V. contectus females, post-copulatory processes ultimately determined the karyotype distribution of the backcross progeny. Homoploidy of all backcross progeny together with the presence of sperm and embryos in their gonads makes gene exchange between the two parental species through hybridization possible.

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Spermatogenesis in a Male Hinny: Histological and Cytological Studies

Cited by 14 publications

References 0 publications

A fertile mule and hinny in China

A fertile mule and hinny in China

Spontaneous seminoma in a mule

Chromosome inheritance and reproductive barriers in backcrosses between two hybridizing Viviparus snail species

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