Results 81 to 90 of about 62,614 (258)

Intraspecific divergence in sperm morphology of the green sea urchin, Strongylocentrotus droebachiensis: implications for selection in broadcast spawners

BMC Evolutionary Biology, 2008
Background Sperm morphology can be highly variable among species, but less is known about patterns of population differentiation within species. Most studies of sperm morphometric variation are done in species with internal fertilization, where sexual ...
Manier Mollie K, Palumbi Stephen R
doaj   +1 more source

Morphophysiological dynamics of the proximal post‐testicular ducts in Crotalus durissus Linnaeus, 1758 (Squamata: Viperidae)

The Anatomical Record, EarlyView.
Abstract The organization and function of reptilian excurrent ducts remain poorly characterized, particularly in Neotropical snakes. We provide the first integrative morphological, histochemical, immunohistochemical, and ultrastructural analysis of the proximal post‐testicular ducts of Crotalus durissus across reproductive stages.
Flávia Cappuccio de Resende, Gustavo Caldeira Cotta, Clara d' Ávila Fonseca Paiva de Paula Freitas, Leonardo Carvalho, Heloísa Helena Marques Oliveira, Victória Gomes Carvalho Silva, Lívia de Fátima Moreira Silva, Luciana Maria Silva, Samyra Maria dos Santos Nassif Lacerda, Guilherme Mattos Jardim Costa   +9 more
wiley   +1 more source

Sperm competition: linking form to function

BMC Evolutionary Biology, 2008
Background Using information from physics, biomechanics and evolutionary biology, we explore the implications of physical constraints on sperm performance, and review empirical evidence for links between sperm length and sperm competition (where two or ...
Simmons Leigh W, Evans Jonathan P, Humphries Stuart   +2 more
doaj   +1 more source

Variable grouping patterns in primates: A test of the better competitor hypothesis in male Verreaux's sifaka (Propithecus verreauxi)

The Anatomical Record, EarlyView.
Abstract Intraspecific variation in social organization (IVSO) within primate populations can arise due to male mating competition. Verreaux's sifaka (Propithecus verreauxi) populations exhibit both single‐male and multi‐male groups, providing an opportunity to examine the relationship between male competitive ability and social organization.
Lemeng Li, Stacey R. Tecot, Rebecca J. Lewis   +2 more
wiley   +1 more source

Selection against spermatozoa with fragmented DNA after postovulatory mating depends on the type of damage

Reproductive Biology and Endocrinology, 2010
Background Before ovulation, sperm-oviduct interaction mechanisms may act as checkpoint for the selection of fertilizing spermatozoa in mammals. Postovulatory mating does not allow the sperm to attach to the oviduct, and spermatozoa may only undergo some
Pintado Belén, Gutiérrez-Adán Alfonso, Fernández-González Raúl, Pérez-Crespo Miriam, Hourcade Juan D   +4 more
doaj   +1 more source

Hormonal control and signaling of the testis of the bat Molossus molossus during the processes of testicular maturation, regression, and recrudescence

The Anatomical Record, EarlyView.
Abstract Molossus molossus, a species of neotropical bat belonging to the Molossidae family, has an annual reproductive cycle that includes two peaks of spermatogenic activity, one in April and another in September, and a period of total testicular regression in December.
Emília M. Soares, Juliana F. Ferraz, Cornélio S. Santiago, Larissa P. R. Venâncio, Arlindo G. Macedo‐Junior, Sebastião R. Taboga, Mateus R. Beguelini   +6 more
wiley   +1 more source

Sperm Separation and Selection Techniques to Mitigate Sperm DNA Damage

Life
Semen preparation and sperm selection techniques exploit the morphological and physiological characteristics of sperm function, including motility, morphology, density, and maturity, as reflected by their cell-surface charge and the expression of hyaluronan receptors. The various methods employed have a common purpose of mimicing sperm selection within
Steven Fleming, David Morroll, Martine Nijs   +2 more
openaire   +3 more sources

The Comparison of Efficiency of Density Gradient Centrifugation and Zeta Methods in Separation of Mature Sperm with Normal Chromatin Structure [PDF]

Cell Journal, 2009
Objective: To examine the efficiency of both the Zeta and density gradient centrifugation(DGC) methods for the selection of normal chromatin sperm by TUNEL, sperm chromatindispersion (SCD), acridine orange and chromomycin A3 (CMA3).Materials and Methods:
Mohammad Hossein Nasr Esfahani, Shahnaz Razavi, Mohammad Mardani, Noush Afarin Khajavi, Mohammad Reza Deemeh, Marziyeh Tavalaee   +5 more
doaj  

Ursolic Acid Alleviates Orchitis via Modulating Ferroptosis in Peritubular Myoid Cells of Testis

Animal Research and One Health, EarlyView.
Ursolic acid modulates key ferroptosis‐related pathways in the peritubular myoid cells of the testis in forest musk deer. ABSTRACT Chronic stress adversely affects reproductive health, increasing susceptibility to pathologies such as orchitis. Additionally, the maintenance of iron homeostasis is essential for preserving the function of the testicles ...
Yang Wang, Tianqi Jin, Zexin Chen, Ye Gong, Qimin Liu, Zifang Wu, Heran Cao, Yan Li, Yuyan Liu, Tianhao Yang, Zhihong Jiang, Wuzi Dong   +11 more
wiley   +1 more source

The Role of miRNAs in Chicken Immune Regulation and Prospects for Disease‐Resistant Breeding

Animal Research and One Health, EarlyView.
A schematic workflow illustrating the screening of disease‐resistant miRNAs and the generation of miRNA‐based disease‐resistant chickens via PGC‐mediated germline genome editing. ABSTRACT MicroRNAs (miRNAs) are emerging as pivotal regulators of the immune system, playing a decisive role in shaping disease resistance in chicken.
Qiangzhou Wang, Weiran Wu, Qingqing Cai, Jiaxing Wang, Qi Gao, Muhammad Iftikhar, Yulin Bi, Hao Bai, Lihong Gu, Guobin Chang, Shihao Chen   +10 more
wiley   +1 more source