Results 91 to 100 of about 2,405,716 (326)

Sexual selection in a transparent worm : insights from fluorescent sperm [PDF]

open access: yes, 2015
Sexual selection is a potent source of selection underlying the evolution of sexual dimorphism, reproductive strategies and mating systems. Although sexual selection was initially thought to occur exclusively at the pre-copulatory stage (e.g., contests ...
Marie-Orleach, Lucas
core   +1 more source

Early stages of tooth development in the harbor porpoise Phocoena phocoena

open access: yesThe Anatomical Record, EarlyView.
Abstract Here we describe the stages of tooth development in toothed whales on the basis of the harbor porpoise (Phocoena phocoena). The aim of the study was to find out whether these stages are identical to those of other mammals analyzed so far although toothed whales are homodont and monophyodont.
Lasse M. Mathes   +2 more
wiley   +1 more source

Temporal trends in sperm count: a systematic review and meta-regression analysis of samples collected globally in the 20th and 21st centuries.

open access: yesHuman Reproduction Update, 2022
H. Levine   +7 more
semanticscholar   +1 more source

Tracing the evolutionary history of the morpho‐anatomy of baculum in primates

open access: yesThe Anatomical Record, EarlyView.
Abstract Animal morphology reflects both evolutionary history and present‐day adaptation. Male mammal copulatory structures such as the baculum (penile bone) are ideal for studying these processes because of their complexity and high interspecific variability. In primates, however, research has focused mostly on baculum length.
Federica Spani   +3 more
wiley   +1 more source

Cryopreservation of Pike Perch Sperm in Hatchery Conditions [PDF]

open access: yes, 2008
Experiments were carried out on pike perch (Sander lucioperca L.) to find a method for stripping sperm without contamination by urine, to determine sperm concentration, and to fertilize large batches of eggs with cryopreserved sperm.
Urbányi, Béla   +3 more
core   +1 more source

Protective Effect of All-Trans Retinoic Acid in Cisplatin-Induced Testicular Damage in Rats

open access: yesThe World Journal of Men's Health, 2019
Purpose: To investigate the effects of all-trans retinoic acid (ATRA) in cisplatin (CP)-induced testicular damage in rats. Materials and Methods: Twenty-eight male Wistar rats were divided into four groups: Control, ATRA alone, ATRA+CP, and CP alone ...
Cem Yucel   +10 more
doaj   +1 more source

Immature germ cells in semen – correlation with total sperm count and sperm motility

open access: yesJournal of Cytology, 2013
Background: Current data regarding infertility suggests that male factor contributes up to 30% of the total cases of infertility. Semen analysis reveals the presence of spermatozoa as well as a number of non-sperm cells, presently being mentioned in ...
P. Patil   +3 more
semanticscholar   +1 more source

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

open access: yesThe 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   +9 more
wiley   +1 more source

Genotype and allele distribution of MTHFR SNPs in relation to sperm count.

open access: yes, 2013
Genotype and allele distribution of MTHFR SNPs in relation to sperm count.
Richa Gupta (365179)   +8 more
core   +1 more source

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

open access: yesThe 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   +6 more
wiley   +1 more source

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