Effect of oocyte maturation time, sperm selection method and oxygen tension on in vitro embryo development in alpacas

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Authors
Ruiz, Jaime
Santayana, R. Paulo
Mendoza, M. Jose
Landeo, J. Leandra
Huaman, Elizabeth
Ticllacuri, Flamel
Mujica, L. Fidel
Silva Jiménez, Mauricio
Ratto, Marcelo H.
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Date
Datos de publicación:
THERIOGENOLOGY,Vol.95,127-132,2017
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Abstract
We evaluated the effect of in vitro maturation time, sperm selection and oxygen tension on alpaca embryo development. In Experiment I, Cumulus Oocyte-Complexes (COCs) were obtained from abattoir ovaries and in vitro matured in TCM-199 for 24 (n = 217), 28 (215), or 32 h (223) at 38.5 degrees C, high humidity and 5% CO2 in air. Oocytes from 24 (n = 392), 28 (n = 456) or 32 (n = 368) h groups were in vitro fertilized with epididymal sperm and cultured in SOFaa at 38.5 degrees C, high humidity and 5% CO2, 5% O-2 and 90% N-2 for 7 days. Embryo development was evaluated on Day 2, 5 and Day 7 of in vitro culture (Day 0 = in vitro fertilization). In Experiment II, a 2 by 2 -factorial design was used to determine the effect of sperm selection (Swim -up vs Percoll) and oxygen tension (20% vs 5%) during embryo culture and their interaction on embryo development. COCs were in vitro matured for 32 h at 38.5 degrees C and 5% CO2 in air and then in vitro inseminated with epididymal sperm processed by swim-up or Percoll. Zygotes were cultured in SOFaa + cumulus cells at 38.5 degrees C under 20 or 5% of O-2 tension and high humidity for 7 days. A total of 235, 235, 253 and 240 oocytes were assigned to: swim-up+20 O-2, swim-up+5 O-2 or Percoll+20 O-2, Percoll+5 O-2, groups respectively. The proportion of oocytes reaching MII stage was highest after 32 h of in vitro maturation (P < 0.05). Blastocyst rate (29.1 +/- 2.7%) was also highest for COCs matured for 32 h (Exp I). In Experiment II, Blastocysts rate (26.03 +/- 4.7; 27.7 +/- 43; 29.7 +/- 3.8 and 27.6 +/- 4.2% for swimup+20 O-2, swim-up+5 O-2 or Percoll+20 O-2, Percoll+5 O-2, respectively) was not affected by sperm selection method (P = 0.8), oxygen tension (P = 0.9) or their interaction (P = 0.5). (C) 2017 Elsevier Inc. All rights reserved.
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