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Delphine Mieulet, Sylvie Jolivet, Maud Rivard, Laurence Cromer, Aurore Vernet, Pauline Mayonove, Lucie Pereira, Gaëtan Droc, Brigitte Courtois, Emmanuel Guiderdoni, Raphael Mercier
Introduction of clonal reproduction through seeds (apomixis) in crops has the potential to revolutionize agriculture by allowing self-propagation of any elite variety, in particular F1 hybrids. In the sexual model plant Arabidopsis thaliana synthetic clonal reproduction through seeds can be artificially implemented by (i) combining three mutations to turn meiosis into mitosis (MiMe) and (ii) crossing the obtained clonal gametes with a line expressing modified CENH3 and whose genome is eliminated in the zygote...
October 21, 2016: Cell Research
Marta R Pereira, Cristian S Dambros, Charles E Zartman
PREMISE OF THE STUDY: Resource allocation is difficult to characterize in plants because of the challenges of quantifying gametes and propagules. We surveyed six sympatric, unisexual species in the family Calymperaceae (Bryophyta) to test for trade-offs in prezygotic sexual and asexual expression and density-dependent survivorship of female gametangia. METHODS: We tallied gametangial and asexual propagule output for 1820 shoots from 17 populations of six species at monthly intervals during one year (2010-2011) in a central Amazonian forest...
October 7, 2016: American Journal of Botany
Thomas Freour, Rita Vassena
: The study of oocyte and preimplantation embryo biology has been regarded with great curiosity throughout scientific history, but it is not until the development of robust methods for in vitro observation and manipulation of animal gametes that developmental biology has flourished as a discipline. By far the biggest technical challenge in studying transcription in oocytes and early embryo has been the necessity of developing techniques that retain a high level of accuracy when starting from small amount of material...
October 17, 2016: Journal of Proteomics
Stella Maris Martin, Ana C Díaz
Heleobia piscium (d'Orbigny, 1835), a member of the Cochliopidae family found only in South America, is distributed from Entre Ríos, Delta del Paraná, and the littoral of the Río de la Plata down as far as to Punta Indio (Buenos Aires), the southernmost limit of the snail's geographical distribution. To date, little information is available regarding the reproductive cycle of species within this family either in Argentina or throughout South America. The present work analyzed the histology of the reproductive system of the gonochoric species H...
2016: PeerJ
C L Ackermann, C S Asa, R Krisher, K Bauman, S Casey, M D Lopes
Cryopreservation of gametes is an important tool to preserve fertility, but for most species, including domestic dogs, data regarding ovarian tissue cryopreservation are limited. We aimed to evaluate the follicular and tissue viability and follicular growth after in vitro culture of domestic dog ovarian cortical slices cryopreserved by vitrification. Ovarian cortex was obtained from ten pairs of ovaries from domestic dogs using two methods (A and B), one for each ovary from the same bitch. At least four slices for each method were obtained from each ovary, one was processed for histology and the other three were vitrified...
October 18, 2016: Reproduction in Domestic Animals, Zuchthygiene
Yves J R Menezo, Erica Silvestris, Brian Dale, Kay Elder
The negative effect of oxidative stress on the human reproductive process is no longer a matter for debate. Oxidative stress affects female and male gametes and the developmental capacity of embryos. Its effect can continue through late stages of pregnancy. Metabolic disorders and psychiatric problems can also be caued by DNA methylation and epigenetic errors. Age has a negative effect on oxidative stress and DNA methylation, and recent observations suggest that older men are at risk of transmitting epigenetic disorders to their offspring...
September 27, 2016: Reproductive Biomedicine Online
Manuela Monti
By putting together the most advanced evidences supporting the 'gamete and embryo-fetal origins of adult diseases' the two editors, Prof. He-Feng Huang and Prof. Jian-Zhong Sheng (Hangzhou, People's Republic of China) did a great workk.....
August 10, 2016: European Journal of Histochemistry: EJH
Boris A López, Erasmo C Macaya, Fadia Tala, Florence Tellier, Martin Thiel
Dispersal on floating seaweeds depends on availability, viability and trajectories of the rafts. In the southern hemisphere, the bull kelp Durvillaea antarctica is one of the most common floating seaweeds, but phylogeographic studies had shown low connectivity between populations from continental Chile, which could be due to limitations in local supply and dispersal of floating kelps. To test this hypothesis, the spatiotemporal dynamics of kelp strandings were examined in four biogeographic districts along the Chilean coast (28°-42°S)...
October 13, 2016: Journal of Phycology
F Kent Hamra
Knowledge gaps persist on signaling pathways and metabolic states in germ cells sufficient to support spermatogenesis independent of a somatic environment. Consequently, methods to culture mammalian stem cells through spermatogenesis in defined systems have not been established. Lack of success at culturing mammalian stem cells through spermatogenesis in defined systems reflects an inability to experimentally recapitulate biochemical events that develop in germ cells during a seminiferous epithelial cycle. Complex germ and somatic cell associations that develop each seminiferous epithelial cycle support such a hypothesis, conceivably explaining why highly pure mammalian spermatogonia have not developed into meiosis, much less through meiosis without somatic cells...
2017: Methods in Molecular Biology
Amanda M Butler, Tristan Aguero, Karen M Newman, Mary Lou King
Primordial germ cells (PGCs) are the precursors to the gametes and have the unique ability to retain full developmental potential. However, the mechanism(s) and gene-network(s) necessary for their proper specification and development are poorly understood. This is due, in part, to the challenges that must be overcome in order to identify and isolate PGCs during critical stages of development. Two distinct mechanisms have been characterized to specify the germ cell lineage in vertebrates: induction and inheritance...
2017: Methods in Molecular Biology
Bruce W Draper
Both male and female zebrafish have a population of germ-line stem cells that produce gametes throughout the life of the fish. These cells localize to specific regions in the gonads and can be identified because they uniquely express the nanos2 gene, which encodes a conserved regulator of translation. A method is presented here for identifying germ-line stem cells in the ovary and testis using a combined protocol for whole-mount fluorescent RNA in situ hybridization to detect nanos2 mRNA and immunofluorescence to detect the pan-germ cell marker Vasa...
2017: Methods in Molecular Biology
Neila Marouani, Olfa Tebourbi, Donia Cherif, Dorsaf Hallegue, Mohamed Tahar Yacoubi, Mohsen Sakly, Moncef Benkhalifa, Khemais Ben Rhouma
The 2,4-dichlorophenoxyacetic acid (2,4-D) is used worldwide in agriculture as a selective herbicide. It has been shown to produce a wide range of adverse effects on the health of both animals and humans from embryotoxicity and teratogenicity to neurotoxicity. In the present study, we have examined the effect of 2,4-D on male reproductive function of rats. Male Wistar rats received daily by force-feeding 100 or 200 mg of 2,4-D/kg body weight for 30 consecutive days. Rats exposed to 100 and 200 mg of 2,4-D/kg showed a significant decrease in body weights only after 24 days of treatment and in relative weights of testis, seminal vesicles and prostate at killing day, when compared with controls...
October 12, 2016: Environmental Science and Pollution Research International
Fu Mei, Xu Kehui, Xu Wenming
Dicer, an RNAse III endonuclease, is critical for the biogenesis of small noncoding RNAs (microRNAs), including the biogenesis of microRNAs and small interfering RNAs, which transcriptionally and post-transcription ally regulate mRNA expression through binding to target mRNA and leading to subsequent mRNA degradation. Recent studies show that Dicer plays important roles in cell proliferation, differentiation and apoptosis. It has been attracted more and more attention in the reproductive field. In the male reproduction field, mouse model shows that Dicer is critical for the development of spermatogenic cell, sperm maturation, sperm motility and morphology...
July 20, 2016: Yi Chuan, Hereditas
Guang Gao, Anthony S Clare, Craig Rose, Gary S Caldwell
The incidence and severity of extraordinary macroalgae blooms (green tides) are increasing. Here, climate change (ocean warming and acidification) impacts on life history and biochemical responses of a causative green tide species, Ulva rigida, were investigated under combinations of pH (7.95, 7.55, corresponding to lower and higher pCO2), temperature (14, 18°C) and nitrate availability (6 and 150μmolL(-1)). The higher temperature accelerated the onset and magnitude of gamete settlement. Any two factor combination promoted germination and accelerated growth in young plants...
October 10, 2016: Marine Pollution Bulletin
Kurt B Petersen, Martin Burd
The primitive land plant life cycle featured the production of spores of unimodal size, a condition called homospory. The evolution of bimodal size distributions with small male spores and large female spores, known as heterospory, was an innovation that occurred repeatedly in the history of land plants. The importance of desiccation-resistant spores for colonization of the land is well known, but the adaptive value of heterospory has never been well established. It was an addition to a sexual life cycle that already involved male and female gametes...
October 11, 2016: Biological Reviews of the Cambridge Philosophical Society
J Matthew Watson, Alexander Platzer, Anita Kazda, Svetlana Akimcheva, Sona Valuchova, Viktoria Nizhynska, Magnus Nordborg, Karel Riha
In plants, gametogenesis occurs late in development, and somatic mutations can therefore be transmitted to the next generation. Longer periods of growth are believed to result in an increase in the number of cell divisions before gametogenesis, with a concomitant increase in mutations arising due to replication errors. However, there is little experimental evidence addressing how many cell divisions occur before gametogenesis. Here, we measured loss of telomeric DNA and accumulation of replication errors in Arabidopsis with short and long life spans to determine the number of replications in lineages leading to gametes...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Wei Li, Yingpeng Guo, Aixiang Zhang, Huaigu Chen
Sharp eyespot on wheat is caused by Rhizoctonia cerealis anastomosis group D subgroup I (AG-DI) and is an economically important stem-base disease of wheat in temperate regions worldwide. However, the understanding about the field population structure of R. cerealis is limited. In this study, the genetic structure of four wheat-infecting populations in China was investigated using six microsatellite markers characterized from the transcriptome data of R. cerealis AG-DI. A total of 173 unique genotypes were identified among 235 fungal isolates...
October 11, 2016: Phytopathology
Raju Murugananthkumar, Yarikipati Prathibha, Balasubramanian Senthilkumaran, Anbazhagan Rajakumar, Hirohiko Kagawa
Gonadal maturation is a critical event wherein gonads, under the influence of several hormones and factors, undergo cyclic morphological and physiological changes to produce functional gametes during the spawning phase. However, artificial induction can be effectively used to advance the maturation of gonad vis-à-vis spawning like behavior in seasonal breeders during the off-breeding season. In the present study, osmotic pumps loaded with 5000IU of human chorionic gonadotropin (hCG) or saline as control were implanted intraperitoneally for 21days during the pre-spawning phase (May-June) in catfish Clarias batrachus and C...
October 5, 2016: General and Comparative Endocrinology
Anupama Prakash, Antónia Monteiro
Secondary sexual traits are those traits other than the primary gametes that distinguish the sexes of a species. The development of secondary sexual traits occurs when sexually dimorphic factors, that is, molecules differentially produced by primary sex determination systems in males and females, are integrated into the gene regulatory networks responsible for sexual trait development. In insects, these molecular asymmetric factors were always considered to originate inside the trait-building cells, but recent work points to external factors, such as hormones, as potential candidates mediating secondary sexual trait development...
October 2016: Current Opinion in Insect Science
David S Rabiger, Jennifer M Taylor, Andrew Spriggs, Melanie L Hand, Steven T Henderson, Susan D Johnson, Karsten Oelkers, Maria Hrmova, Keisuke Saito, Go Suzuki, Yasuhiko Mukai, Bernard J Carroll, Anna M G Koltunow
BACKGROUND: Application of apomixis, or asexual seed formation, in crop breeding would allow rapid fixation of complex traits, economizing improved crop delivery. Identification of apomixis genes is confounded by the polyploid nature, high genome complexity and lack of genomic sequence integration with reproductive tissue transcriptomes in most apomicts. RESULTS: A genomic and transcriptomic resource was developed for Hieracium subgenus Pilosella (Asteraceae) which incorporates characterized sexual, apomictic and mutant apomict plants exhibiting reversion to sexual reproduction...
October 6, 2016: BMC Biology
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