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Jenniffer Puerta Suárez, Stefan S du Plessis, Walter D Cardona Maya
The 100,000th scientific article on the subject of spermatozoa was recently published. Numerous studies evaluated the characteristics of this important cell that led to tremendous discoveries. Since its first observation and description in 1677, many important characteristics have been described regarding this highly fascinating gamete. In this review, we intend to provide a historical account of the numerous milestones and breakthroughs achieved related to spermatozoa. We conducted a review of the literature by selecting the most important subjects with regards to spermatozoa...
June 2018: International Journal of Fertility & Sterility
Jessica R Sanders, Keith T Jones
Initiated by luteinizing hormone and finalized by the fertilizing sperm, the mammalian oocyte completes its two meiotic divisions. The first division occurs in the mature Graafian follicle during the hours preceding ovulation and culminates in an extreme asymmetric cell division and the segregation of the two pairs of homologous chromosomes. The newly created mature egg rearrests at metaphase of the second meiotic division prior to ovulation and only completes meiosis following a Ca2+ signal initiated by the sperm at gamete fusion...
June 22, 2018: Biochemical Society Transactions
Pearl Chang, Yu-Fang Tseng, Pao-Yang Chen, Chung-Ju Rachel Wang
Meiosis is essential during sexual reproduction to generate haploid gametes. Genomic or epigenomic studies of meiosis in multicellular organisms using next-generation sequencing (NGS) methods have been limited because of the difficulty of collecting thousands to millions of meiocytes. Here, we describe a simple protocol to efficiently isolate maize male meiocytes from formaldehyde-fixed samples for NGS techniques that require chemical crosslinking to preserve complex interactions or chromatin architecture. Anthers at desired meiotic stages are selected, fixed with paraformaldehyde, and disrupted using a homogenizer...
June 2018: Current Protocols in Plant Biology
Ruiqi Li, Songbang Ou, Nengyong Ouyang, Lingyan Zheng, Qingxue Zhang, Dongzi Yang, Wenjun Wang
PURPOSE: The objective of this study was to determine whether ammonium accumulates in IVF media during fertility process and whether the brief co-incubation of gametes (bIVF) benefited the outcomes of newborns. METHODS: Ammonium levels in IVF media during gamete co-incubation were measured and the effects of bIVF on neonatal outcomes were evaluated retrospectively in this study. RESULTS: A total of 609 live newborns cycles were included in this study...
June 20, 2018: Journal of Assisted Reproduction and Genetics
Luke Browne, Kym Ottewell, Victoria L Sork, Jordan Karubian
Seed and pollen dispersal shape patterns of gene flow and genetic diversity in plants. Pollen is generally thought to travel longer distances than seeds, but seeds determine the ultimate location of gametes. Resolving how interactions between these two dispersal processes shape micro-evolutionary processes is a long-standing research priority. We unambiguously isolated the separate and combined contributions of these two dispersal processes in seedlings of the animal-dispersed palm Oenocarpus bataua to address two questions...
June 20, 2018: Molecular Ecology
Hongyan Xu, Xinping Zhu, Wei Li, Zhoukai Tang, Yanyan Zhao, Xuling Wu
Gonadal cell lines provide valuable tools for studying gametogenesis, sex differentiation, and manipulating germ cells in reproductive biology. Female germline stem cells have been characterized and isolated from ovaries of mammalian species, including mice and human, but there has been very few studies on female germline stem cells in reptiles. Here, we described an ovarian stem cell-like line isolated and cultured from the Chinese soft-shell turtle (Pelodiscus sinensis), designated as PSO1. The cells showed high alkaline phosphatase activity with a normal diploid karyotype...
June 20, 2018: Journal of Cellular Biochemistry
April M Randle, Rachel B Spigler, Susan Kalisz
Coexisting plant congeners often experience strong competition for resources. Competition for pollinators can result in direct fitness costs via reduced seed set or indirect costs via heterospecific pollen transfer (HPT), causing subsequent gamete loss and unfit hybrid offspring production. Autonomous selfing may alleviate these costs, but to preempt HPT, selfing should occur early, before opportunities for HPT occur (i.e. "preemptive selfing hypothesis"). We evaluated conditions for this hypothesis in Collinsia sister species, C...
June 19, 2018: Evolution; International Journal of Organic Evolution
L Touazi, B Aberkane, Y Bellik, N Moula, M Iguer-Ouada
Aim: This study aimed to investigate the protective effect of Rosmarinus officinalis (L.) essential oil on rooster sperm motility during 4°C short-term storage. Materials and Methods: R. officinalis essential oil was analyzed using gas chromatography coupled to mass spectrometry to identify the active components. 10 of 45-week-old Hubbard commercial broilers were subjected to biweekly semen collections during 3 weeks. At each collection, sperm was pooled and divided into four aliquots and then diluted with Tris extender supplemented with 870, 87, or 8...
May 2018: Veterinary World
Z Jiang, J Lin, H Dong, X Zheng, S L Marjani, J Duan, Z Ouyang, J Chen, X C Tian
DNA methylation is an important epigenetic modification that undergoes dynamic changes in mammalian embryogenesis, during which both parental genomes are reprogrammed. Despite the many immunostaining studies that have assessed global methylation, the gene-specific DNA methylation patterns in bovine preimplantation embryos are unknown. Using reduced representation bisulfite sequencing, we determined genome-scale DNA methylation of bovine sperm and individual in vivo developed oocytes and preimplantation embryos...
June 14, 2018: Biology of Reproduction
Junyan Sun, Ying Guo, Qiuwan Zhang, Shixia Bu, Boning Li, Qian Wang, Dongmei Lai
Psychological stress, which exerts detrimental effects on human reproduction, may compromise the meiotic competence of oocytes. Meiotic resumption, germinal vesicle breakdown (GVBD), is the first milestone to confer meiotic competence to oocytes. In the practice of assisted reproductive technology (ART), the timing for GVBD is associated with the rates of cleavage and blastocyst formation. However, whether chronic stress compromises oocyte competence by influencing GVBD and the underlying mechanisms are unclear...
June 18, 2018: Cell Cycle
(no author information available yet)
Posthumous gamete (sperm or oocyte) retrieval or use for reproductive purposes is ethically justifiable if written documentation from the deceased authorizing the procedure is available. Retrieval of sperm or eggs does not commit a center to their later use for reproduction, but may be permissible under the circumstances outlined in this opinion. Embryo use is also justifiable with such documentation. In the absence of written documentation from the decedent, programs open to considering requests for posthumous use of embryos or gametes should only do so when such requests are initiated by the surviving spouse or partner...
June 13, 2018: Fertility and Sterility
Simon Fishel
On July 25, 1978, the first human was born following extracorporeal fertilization, an event that opened up a new medical science: expanding our knowledge of and developing novel treatments for infertility, radically changing the opportunities for families with inherited monogenic disorders, generating the new discipline of clinical embryology, and paving the way for studies into stem cell biology. In vitro fertilization (IVF), as it became known in its simplest form, went even further: it engaged the myriad of minds in human society...
June 13, 2018: Fertility and Sterility
David A Landry, Lia Rossi-Perazza, Simon Lafontaine, Marc-Andre Sirard
The use of younger gamete donors in dairy cattle genetic selection programs significantly accelerates genetic gains by decreasing the interval between generations. Ovarian stimulation and the practice of follicle-stimulating hormone (FSH) withdrawal, also known as coasting, are intensively used in pre-pubertal heifers without detrimental effects on subsequent reproductive performance but generally with lower embryo yields. However, recent data from embryo transfer programs showed similar embryo yields in younger and sexually mature animals but with a significant difference in the coasting period...
June 15, 2018: Reproduction: the Official Journal of the Society for the Study of Fertility
Erin E Higgins, Wayne E Clarke, Elaine C Howell, Susan J Armstrong, Isobel A P Parkin
The heavy selection pressure due to intensive breeding of Brassica napus has created a narrow gene pool, limiting the ability to produce improved varieties through crosses between B. napus cultivars. One mechanism that has contributed to the adaptation of important agronomic traits in the allotetraploid B. napus has been chromosomal rearrangements resulting from homoeologous recombination between the constituent A and C diploid genomes. Determining the rate and distribution of such events in natural B. napus will assist efforts to understand and potentially manipulate this phenomenon...
June 15, 2018: G3: Genes—Genomes—Genetics
David López-Escardó, Jordi Paps, Colomban de Vargas, Ramon Massana, Iñaki Ruiz-Trillo, Javier Del Campo
Although animals are among the best studied organisms, we still lack a full description of their diversity, especially for microscopic taxa. This is partly due to the time-consuming and costly nature of surveying animal diversity through morphological and molecular studies of individual taxa. A powerful alternative is the use of high-throughput environmental sequencing, providing molecular data from all organisms sampled. We here address the unknown diversity of animal phyla in marine environments using an extensive dataset designed to assess eukaryotic ribosomal diversity among European coastal locations...
June 14, 2018: Scientific Reports
Carmen González-Fernández, Kevin Tallec, Nelly Le Goïc, Christophe Lambert, Philippe Soudant, Arnaud Huvet, Marc Suquet, Mathieu Berchel, Ika Paul-Pont
While the detection and quantification of nano-sized plastic in the environment remains a challenge, the growing number of polymer applications mean that we can expect an increase in the release of nanoplastics into the environment by indirect outputs. Today, very little is known about the impact of nano-sized plastics on marine organisms. Thus, the objective of this study was to investigate the toxicity of polystyrene nanoplastics (NPs) on oyster (Crassostrea gigas) gametes. Spermatozoa and oocytes were exposed to four NPs concentrations ranging from 0...
June 6, 2018: Chemosphere
Luke Browne, Jordan Karubian
Habitat loss and fragmentation often reduce gene flow and genetic diversity in plants by disrupting the movement of pollen and seed. However, direct comparisons of the contributions of pollen vs. seed dispersal to genetic variation in fragmented landscapes are lacking. To address this knowledge gap, we partitioned the genetic diversity contributed by male gametes from pollen sources and female gametes from seed sources within established seedlings of the palm Oenocarpus bataua in forest fragments and continuous forest in northwest Ecuador...
June 13, 2018: Molecular Ecology
Rowan A Lymbery, W Jason Kennington, Jonathan P Evans
The widespread prevalence of sperm competition means that ejaculates face intense sexual selection. However, prior investigations of sexual selection on gametes have been hampered by two difficulties: (1) deriving estimates of relative fitness from sperm competition trials that are comparable across rival male and female genotypes and (2) obtaining measures of competitive fertilization success that are not confounded by postzygotic effects. Here, we exploit the experimental tractability of a broadcast spawning marine invertebrate to overcome these challenges and characterize multivariate sexual selection on sperm traits when multiple ejaculates compete...
July 2018: American Naturalist
Louis Flamand
Upon infection and depending on the infected cell type, human herpesvirus 6A (HHV-6A) and 6B (HHV-6B) can replicate or enter a state of latency. HHV-6A and HHV-6B can integrate their genomes into host chromosomes as one way to establish latency. Viral integration takes place near the subtelomeric/telomeric junction of chromosomes. When HHV-6 infection and integration occur in gametes, the virus can be genetically transmitted. Inherited chromosomally integrated HHV-6 (iciHHV-6)-positive individuals carry one integrated HHV-6 copy per somatic cell...
2018: Advances in Experimental Medicine and Biology
Bing Bu, Michael Crowe, Jiajie Diao, Baohua Ji, Dechang Li
Membrane fusion is a fundamental biological process that lies at the heart of enveloped virus infection, synaptic signaling, intracellular vesicle trafficking, gamete fertilization, and cell-cell fusion. Membrane fusion is initiated as two apposed membranes merge to a single bilayer called a hemifusion diaphragm. It is believed that the contents of the two fusing membranes are released through a fusion pore formed at the hemifusion diaphragm, and yet another possible pathway has been proposed in which an undefined pore may form outside the hemifusion diaphragm at the apposed membranes, leading to the so-called leaky fusion...
June 13, 2018: Soft Matter
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