Do Computer‐Assisted, Morphometric‐Derived Sperm Characteristics Reflect DNA Status in Canine Spermatozoa?

Abstract

It is widely accepted that sperm morphology is a strong indicator of semen quality. As the sperm head mainly comprises the sperm DNA, it is have been proposed that subtle changes in sperm morphology may be related to abnormal DNA content. Semen from four mongrel dogs was used to investigate DNA quality by means of the sperm chromatin structure assay (SCSA), and for computerized sperm morphometry (CASMA). Each sperm head was measured for nine primary parameters [head area (A), head perimeter (P), head length (L), head width (W), midpiece width (w), midpiece area (a), distance (d) between the major axes of the head and midpiece, angle (theta) of divergence of the midpiece from the head axis] and four parameters of head shape [FUN1, L/W; FUN2, 4piA/P(2); FUN3, (L - W)/(L + W); FUN4, piLW/4A]. Significant differences were found in all CASMA-derived parameters among dogs (p < 0.001). Linear regression models including sperm head shape factors 1, 3 and 4 predicted the extent of DNA denaturation (p < 0.001). We conclude that the CASMA analysis can be considered a powerful tool to improve the spermiogram.

CASA derived human sperm abnormalities: correlation with chromatin packing and DNA fragmentation

“…Further, any subtle changes in sperm chromatin condensation or alteration in sperm histone-protamine ratio necessary for chromatin packing may directly reflect in changes in head morphology and morphometry [10]. Experimental studies have demonstrated a positive correlation between abnormal sperm head morphology and DNA damage and chromatin integrity, but such relationship in infertile patients was not extensively studied [11][12][13]. To our knowledge, this is one of the few studies which compared and analyzed retrospectively, the correlation of sperm head morphology parameters assessed by CASA with DNA fragmentation analysis and chromatin integrity in infertile patients.…”

Optimal inclusion level of butylated hydroxytoluene in semen extender improves the quality of post-thawed canine sperm

“…An increasing interest and attempts for improvement in semen cryobiology of canines in last five years (Yu et al, 2002;Núñez-Martínez et al, 2005Neagu et al, 2010) have led to well-established cryoprotective protocols allowing better whelping rates (over 70%) (Thomassen et al, 2006) and artificial insemination (AI) of bitches with frozen-thawed semen is now being offered as a routine clinical service by many veterinarians world-wide (Yu et al, 2002).…”

Induced immotility during long-term storage at +5°C does not prolong survival of dog spermatozoa

“…Perez-Llano et al (2006) [18] found that sperm extenders delay, or partially prevent, sperm DNA fragmentation in boar spermatozoa. A strong correlation between the sperm chromatin structure assay (SCSA) and sperm head morphometry in dog spermatozoa has been found [19], but so far, only one study has been published on DNA fragmentation of dog semen [20]. Epididymal sperm and ejaculated semen from Iberian deer, dogs, and rams was collected, diluted with Tris Sodium Chloride Ethylene-diamine-tetra-acetic Acid (TNE) buffer and preserved in LN 2 in an ultra cold freezer (-80ºC).…”

“…Results were analyzed using least square means (LSMs). Period 1 included days 1-8; period 2 included days 9-14; and period 3 included days [15][16][17][18][19][20][21][22][23]. Different superscript letters (a-c) indicate differences (P<0.05) among the extenders.…”

“…The third replicate was examined for presence of bacteria. For the statistical calculations, the 23 experimental days were divided into three periods, the first period comprising days 1-8, the second period days 9-14, and the third period days [15][16][17][18][19][20][21][22][23]. Total motility (TM%) did not differ between extenders in the first period, but was higher in TG and TG+A TG compared with CL+A CL in the second and third periods, and with CL in the third period (P<0.05).…”