131 EFFECTS OF HIGH MOLECULAR WEIGHT HYALURONAN ON SHEEP EMBRYO DEVELOPMENT AND SURVIVAL AFTER CRYOPRESERVATION
V. Ghaffarilaleh A C , F. Ghafari B , M. Teresa-Paramio C and A. Fouladi-Nashta AA Royal Veterinary College, Hatfield, United Kingdom;
B Walsgrave University Hospital, Coventry, United Kingdom;
C Universitat Autonoma de Barcelona, Bellaterra, Cerdanyola del Vallès, Spain
Reproduction, Fertility and Development 25(1) 213-213 https://doi.org/10.1071/RDv25n1Ab131
Published: 4 December 2012
Abstract
Hyaluronan (HA), a component of extracellular matrix in mammalian tissues including that of the reproductive system, has been shown to support embryo development. HA is produced in various sizes with distinct physiological functions. Cleaved sheep embryos produced after in vitro maturation and in vitro fertilization were cultured in serum free synthetic oviduct fluid medium supplemented with increasing concentrations (0, 0.25, 0.5, and 1 mg mL–1) of large size HA (Healon; 6 × 106 Da). Development to blastocyst stage was recorded at Day 7 when a group of the embryos were fixed and stained by differential staining combined with TUNEL labelling to analyse embryo quality. The remainder of the blastocysts from each treatment/repeat were vitrified in open pulled straws and then cultured for an extra period of 48 h to analyse their survival rate and quality after cryopreservation. SPSS version 20 software (SPSS Inc., Chicago, IL, USA) was used for analyzing the data with generalized linear model. Healon did not change blastocyst (33 ± 5.7, 32 ± 6.0, 35 ± 5.5; P ≥ 0.05) or survival rates (63 ± 17.1, 83 ± 15.2, 58 ± 14.2; P ≥ 0.05) as compared to the respective controls (25 ± 5.2, 38 ± 17.1). It increased the total cell (TC) number (83.6 ± 4.6, 100.7 ± 3.8, 97.2 ± 3.7, 105.0 ± 3.9; P ≤ 0.05) and trophectoderm cells (TE) (58.4 ± 3.8, 74.2 ± 3.2, 75.6 ± 3.3, 80.1 ± 3.4; P ≤ 0.05) but had no effect on the number of inner cell mass (ICM) and apoptotic cells. The ICM : TE ratio was not affected (0.45 ± 0.04, 0.36 ± 0.03, 0.33 ± 0.03, 0.30 ± 0.03; P ≥ 0.05). Surviving embryos had higher TC (63.2 ± 3.7, 130.8 ± 3.6, 113.9 ± 5.2, 149.8 ± 5.4; P ≤ 0.05), TE (42.9 ± 3.0, 96.7 ± 3.1, 85.2 ± 4.5, 111.9 ± 4.7; P ≤ 0.05) and ICM (20.3 ± 2.2, 32.9 ± 1.8, 27.7 ± 2.6, 36.5 ± 2.7; P ≤ 0.05). The apoptotic cell numbers and ICM : TE ratio of the survived embryos after cryopreservation were not affected by HA supplementation. The results indicate that large size HA improves the embryo viability and quality, which may have implication for improving embryo transfer.
