title: Separation of motile sperm for in vitro fertilization from frozen-thawed bull semen using progesterone induction on a microchip.
abstract: This study presents a novel method for the separation of motile sperm from non-progressive motile and immotile sperm and in vitro Fertilization (IVF). This separation of bull sperm was accomplished by inducing chemotaxis along a progesterone release agent in a 7.5-mm microchannel microchip composed of a biocompatible polydimethysiloxane layer and a glass gradient. The selected sperm was applied directly for IVF. In the first experiment, we tested the effect of different lengths of microchannnel (5mm, 7.5mm and 10mm) on quality parameter of separated sperm. The results showed that separated sperm using 7.5-mm microchannel chip were improved in sperm motility, swimming velocity, and beat frequency compared with other groups. In the second experiment, a medium containing sperm from swim-up method and outlet reservoir of our 7.5-mm microchannel chip was collected and mitochondrial activity of the sperm was determined by fluorescence microscopy. The sperm from the microchip had higher mitochondria activity (47.6%±6.0%) than the sperm from the swim-up method (23.6%±4.7%) (P<0.05). There were significant differences in rate of acrosome intactness between the swim-up method and the microchip (36.0%±4.1% vs. 66.8±2.1%, respectively, P<0.05). In the third experiment, we compared sperm penetration in the microchip-IVF system with a standard IVF method (droplet-IVF). The microchip-IVF group had the highest percentages of oocytes penetrated (82.2%±1.6% vs. 63.5%±2.4%) and monospermic oocytes (67.8%±3.4% vs. 42.4%±1.5%). In addition, early developmental competence of oocytes to the blastocyst stage was higher when the oocytes were inseminated in the microchip-IVF system compared with those inseminated in a standard droplet-IVF system. These results demonstrate that our microchip based on a sperm chemotaxis system is useful for motile sperm separation from frozen-thawed bull semen for IVF. Therefore, the optimized microchip system provides a good opportunity to sort motile bull sperm for IVF.
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Jingchun
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Bolin
authors.initials: B
authors.lastname: Ning
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Xinyan
authors.initials: X
authors.lastname: Cao
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Luo
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Wei
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Shengjun
authors.initials: S
authors.lastname: Liu
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Aizhong
authors.initials: A
authors.lastname: Zhang
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wu
authors.affiliation: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, PR China. Electronic address: elj863@163.com.
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Li
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D002633:Chemotaxis; D018920:Coculture Techniques; D015925:Cryopreservation / Q000662:veterinary; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D056656:Lab-On-A-Chip Devices / Q000662:veterinary*; D008297:Male; D009865:Oocytes; D011374:Progesterone / Q000494:pharmacology*; D012662:Semen Preservation / Q000662:veterinary*; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000502:physiology*
chemical_list: D011374:Progesterone
keywords: IVF; Microchip; Mitochondria; Motile sperm; Progesterone induction; Separation