Quantitative light and scanning electron microscopy of ferret sperm

Abstract

Sperm were obtained via electroejaculation from Domestic ferret, (Mustela putorius furo), Siberian ferret (M. eversmanni), Black-footed ferret (M. nigripes), and a hybrid between Siberian and Domestic, called the Fitch ferret (M. sp.). Comparisons of sperm were made by four different microscopy techniques to determine whether differences exist among species. First, Nomarski differential interference microscopy could be used to distinguish domestic ferret sperm from the others on the basis of the structure of the posterior part of the acrosome. Second, both silver staining, which demonstrates argentophilic protein distribution, and scanning electron microscopy (SEM), revealed differences among the morphology of sperm for each species; variation in the unique appearance of the acrosome in ferret sperm was detected especially well by SEM. To quantify differences in morphology, five sperm head parameters were measured using image analysis; light microscopy produced significantly larger values than did SEM (all parameters and all species but Fitch), and there were significant differences owing to species for all parameters but one. Generally, our data demonstrate the value of complementary techniques to distinguish among sperm of closely related species and more specifically may help establish evolutionary relationships among the ferret species studied. In addition, they provide baseline data important for the captive breeding of the endangered Black-footed ferret.

Sperm structure and motility in the eusocial naked mole-rat, Heterocephalus glaber: a case of degenerative orthogenesis in the absence of sperm competition?

“…For example, van der Horst et al [32] showed that acrosome structure and shape can be used to distinguish among four very closely related ferret species. Breed [33,34] has furthermore shown that sperm head structure is related to phylogenetic relationships in rodents in addition to their phylogenetic derivation (primitive versus advanced structures).…”

Spermatozoa Characteristics in Six Psittacine Species Using Light Microscopy

“…The same is true for measurements of a complete spermatozoon tail, which is rarely possible using TEM contrary to SEM or LM. On the other hand it is likely to get shrinked spermatozoa using SEM (Van der Horst et al. 1991).…”

Recent advances in bird sperm morphometric analysis and its role in male gamete characterization and reproduction technologies

“…However, this usually requires the use of phosphate-buffered glutaraldehyde solutions to fix the sample, followed by dehydration in ascending concentrations of ethanol,57 and this can strongly affect sperm morphometric variables. Indeed, shrinkage often occurs when biological material is prepared for electron microscopy 58. This may explain why both chicken and turkey sperm morphometric variables are usually recorded as smaller when examined in the electron microscope5354 than in the light microscope 557…”