Influence of Selected Extenders for Liquid Storage at 4ºC of Breeding Chinchilla (<I>Chinchilla lanigera</I>) Semen on Sperm DNA Integrity

Abstract

Influence of selected extenders for liquid storage at 4ºC of breeding chinchilla (Chinchilla lanigera) semen on sperm DNA integrity. Folia Biologica (Kraków) 63: 279-287. The influence of two commercial and two laboratory oriented extenders on survival rate and DNA integrity of chinchilla (Chinchilla lanigera) sperm was determined during liquid storage. Semen was collected using an electroejaculator from 6 adult male chinchillas. Ejaculates (n=16) were diluted with extenders to obtain a concentration of 40×10 ! sperm/5 µl. After dilution the semen samples were stored at 4ºC. The percent motility, progressive motility, and morphology were assessed conventionally, whereas DNA integrity was evaluated by Single Cell Gel Electrophoresis (comet) assay at 0 (just after dilution), 24, 48 and 72 h. Conventional assessment of sperm quality showed that commercial extenders are characterized by the lowest sperm survival parameters out of the investigated extenders. In commercial extenders spermatozoa lost their capacity for progressive motility compared to laboratory extenders. After 24 h storage, from 21.67% to 30% of motile sperms were observed in commercial extender whereas total sperm motility was 63.33% (41.67% with progressive motility) in samples in which stallion semen extender was used. After 72 h storage, 10% of sperm were motile in stallion semen extender while no sperm movement was observed in tubes containing the commercial extender. Furthermore, a lower percentage of damaged spermatozoa in laboratory oriented extenders was demonstrated. It was also stated that along with the extended time of semen storage at 4ºC, commercial extenders lost their protective action. An analysis of DNA content in the heads of sperm cells and tail moment (TM) showed that the most useful extender for liquid preservation of chinchilla semen was the extender for stallions.

Comparison of the characteristics of chinchilla epidydimal semen after collection, storage at 5°C and cryopreservation

“…Loss of motility and viability after preservation was not surprising and was reported for chinchilla semen previously (Carrascosa et al, 2001;Niedbała et al, 2015;Ponce et al, 1998;Ponzio et al, 2007). CASA evaluation used in this study revealed that additionally to the loss of motility, after preservation spermatozoa slowed down and curved their trajectories, which pattern of changes was observed also in other species (Jayaprakash, Patil, Kumar, Majumdar, & Shivaji, 2001;O'Connell, McClure, & Lewis, 2002).…”

“…Semen quality and preservation have been poorly studied in chinchillas, with only several reports exploring this subject (Barnabe et al, 1994;Carrascosa et al, 2001;Niedbała et al, 2015;Ponce et al, 1998;Ponzio, Busso, Ruiz, & Fiol de Cuneo, 2007). By using computerassisted and flow cytometric approach in this study (for the first time for chinchilla epididymal sperm), we have assessed in detail changes in spermatozoa stored at 5°C and cryopreserved.…”

“…There are several studies examining quality of semen stored in liquid state and cryopreserved (Carrascosa et al., ; Niedbała et al., ; Ponce et al., ), but detailed sperm characteristics after preservation are still poorly investigated. For instance, there is no information on motion parameters, oxidative stress, capacitation or apoptotic changes neither in fresh sperm cells nor chilled nor frozen‐thawed.…”

“…Most studies about chinchilla semen were conducted on spermatozoa obtained by electroejaculation (Barnabe, Duarte, Barnabe, Visintin, & de Frettas, 1994;Busso et al, 2005;Carrascosa et al, 2001;Niedbała et al, 2015;Ponzio, Busso, de Cuneo, Ruiz, & Ponce, 2008) and only one described spermatozoa collected from epididymis (Ponce et al, 1998). In chinchillas epididymal sperm can be obtained only after testicle removal (after castration or death), which makes this method useless in the case of active stud males.…”

Comparison of the structure of chinchilla sperm isolated from semen and from the tail of the epididymis

“…Chinchilla lanigera is an endangered species in its natural environment (Leal & Franca, ). Chinchillas were brought to Poland in the 1950s, and since that time breeding of these rodents has become an important branch of agriculture (Niedbała et al, ). Chinchillas are also bred by amateurs as pets.…”