Seminal Plasma Components in Camelids and Comparisons with Other Species

Abstract

Contents Camelid semen is characterized by a highly viscous, low‐volume ejaculate with a low concentration of spermatozoa that exhibit low progressive motility. The viscous seminal plasma is currently the major impediment to the development of assisted reproductive technologies (ARTs) in camelids. To advance ARTs such as sperm cryopreservation and artificial insemination in camelids, it is necessary to identify the cause of the viscosity and gain an understanding of the role of seminal plasma components on sperm function and fertility. Numerous compounds and proteins have been identified as mediators of sperm function and predictors of fertility in other livestock species, and understanding the importance of specific proteins has progressed the success of ARTs in these species. Current knowledge on the components of camelid seminal plasma is outlined, together with the implications of these components for the development of ARTs in camelids. The cause of semen viscosity, as well as proteins that are present in camelid seminal plasma, is described for the first time. Seminal plasma components are compared with those of other species to hypothesize their role in sperm function and fertility.

Evaluation of the cryoprotective effect of seminal plasma on llama ( Lama glama) spermatozoa

“…These authors used 50% SP in the cryopreservation extender, a similar concentration to one of the final concentrations used in the present study. The different results among species, regarding the presence or not of a cryoprotective effect of SP could be due to a species‐specific response of spermatozoa exposed to SP, possibly due to differences both in sperm physiology and in SP composition (Kershaw‐Young & Maxwell, ). Different composition in SP has been demonstrated even between individuals of the same species, and some have hypothesised that this could be involved in the response of spermatozoa to freeze–thawing (Caballero et al, ; Gürler, Calisici, & Bollwein, ).…”

“…On the other hand, a llama seminal lectin (SL15) that is likely adsorbed to spermatozoa via SP during ejaculation and is probably involved in sperm reservoir formation (Zampini, Sequeria, Argañaraz, & Apichela, ). In other species, some components of SP have been shown to act as protective agents against premature capacitation, which would seem to indicate the need to add a certain percentage of SP to cryopreservation diluents (Du et al, ; Kershaw‐Young & Maxwell, ). All the above denotes the important role of SP in reproductive physiology.…”

SL15: A seminal plasma‐derived lectin from the sperm of llama (Lama glama)

“…Very little information is available about the composition and function of the seminal plasma of South American camelids (Apichela et al, 2014;Kershaw-Young & Maxwell, 2012;Ratto, Delbaere, Leduc, Pierson, & Adams, 2011). One particular feature that could affect the application of reproductive technologies on these camelids is their lack of vesicular glands: they only possess a prostate and two bulbourethral glands (Tibary & Anouassi, 1997).…”

Detection of the Matrix Metalloproteinases MMP‐2 and MMP‐9 and Tissue Inhibitors of Metalloproteinases TIMP‐1 and TIMP‐2 in Llama (Lama glama) Oviduct

“…SAC semen is characterized by its viscosity and mucous consistency, condition that impedes the homogenous mixing of semen with extender, thereby restricting contact between the sperm cell membrane and cryoprotective compounds during cryopreservation. Recent studies suggest that the glycosylated protein mucin 5B causes the mucous consistency in alpaca semen (Kershaw‐Young and Maxwell ). This finding supports the fact that many proteases have proven to be effective in reducing the viscosity of camelid seminal plasma (Bravo et al.…”