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- Koonjaenak, S., et al.
(författare)
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Seasonal variation in nuclear DNA integrity of frozen-thawed spermatozoa from Thai AI swamp buffaloes (Bubalus bubalis)
- 2007
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Ingår i: Journal of Veterinary Medicine A. - : Wiley-Blackwell. - 0931-184X .- 1439-0442. ; 54:7, s. 377-383
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we investigated the susceptibility of frozen-thawed swamp buffalo sperm nuclear DNA to undergo controlled acid-induced denaturation in situ, as analysed by flow cytometry, and aimed to correlate the results with sperm head morphology over three seasons in tropical Thailand. Artificial insemination (AI) doses (n = 218) from 18 AI buffalo sires, prepared between 1980 and 1989 and 2003 and 2005, were tested and compared among three seasons, the rainy season, July-October; winter, November-February; and summer , March-June. The overall mean of DNA fragmentation index (DFI) (+/- SD) was 1.84 +/- 1.68%, range from 0.19 to 7.92%, with 0.221 +/- 0.021 of the x-DFI ranging from 0.190 to 0.350 and 0.023 +/- 0.009 of the SD-DFI ranging from 0.010 to 0.070. The DFI was consistently low (range 1.40 +/- 0.21% to 2.16 +/- 0.21%; LSM +/- SEM), with x-DFI ranging from 0.216 +/- 0.003 to 0.225 +/- 0.003 and SD-DFI ranging from 0.022 +/- 0.001 to 0.024 +/- 0.001 across the seasons. The DFI was low enough to be related to high fertility potential. However, DFI values varied statistically among seasons, being lower in the rainy season (1.40 +/- 0.21%, P less than 0.05) than in winter (2.16 +/- 0.21%) or summer (2.00 +/- 0.20%), and were also affected by the year of semen collection and processing (P less than 0.001). The proportion of morphologically abnormal sperm head shapes was low, with no significant differences between seasons. However, DFI was significantly related to the proportion of loose abnormal sperm heads (r = 0.27, P less than 0.01). In conclusion, frozen-thawed swamp buffalo sperm chromatin integrity is not seriously damaged by cryo-preservation or affected by the seasonal variations in temperature and humidity seen in tropical Thailand.
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| 2. |
- Koonjaenak, S., et al.
(författare)
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Seasonality affects post-thaw plasma membrane intactness and sperm velocities in spermatozoa from Thai AI swamp buffaloes (Bubalus bubalis)
- 2007
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Ingår i: Theriogenology. - : Elsevier. - 0093-691X .- 1879-3231. ; 67:9, s. 1424-1435
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Tidskriftsartikel (refereegranskat)abstract
- Altogether 218 frozen semen Al doses, prepared between 1980 and 1989 and also between 2003 and 2005 from 18 Al Thai swamp buffalo sires, were examined to determine whether seasonality affects post-thaw viability, as plasma membrane integrity (PMI, using SYBR-14/PI), plasma membrane stability (PMS, using Annexin-V/PI), or motility (Mot, using CASA). A thermoresistance test (38 degrees C for 60 min) was used to further analyze sperm survivability in vitro. All variables were compared over 3 seasons of the year (rainy: July-October; winter: November-February; and summer: March-June), with distinct ambient temperature and humidity. PMI (% of alive spermatozoa) was higher in winter (54.6%, P less than 0.001) than in the rainy (43.5%) or summer (46.7%) seasons. Outcomes of PMS (Annexin-V/PI assay) confirmed those of PMI, the highest PMS in spermatozoa processed in winter (55.7%, P less than 0.001). Spermatozoa depicting linear Mot post-thaw ranged from 48.2% to 48.8% across seasons (ns), proportions that decreased during incubation (33.5-37.9%), albeit without seasonal differences. The mean percentages of straight linear velocity (VSL), average path velocity (VAP), or curvilinear velocity (VCL) were higher (P less than 0.05-0.001) in the rainy season than in winter or summer, while average lateral head displacement (ALH) was higher (P less than 0.05) in summer, differences maintained after incubation. In conclusion, post-thaw PMS and PMI, assessed by flow cytometry, were significantly better in sperm samples processed during winter than in samples processed during the other seasons of the year, a seasonal difference not picked up by CASA, probably due to the larger number of spermatozoa assessed. (C) 2007 Elsevier Inc. All rights reserved.
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