Mechanical incompatibility caused by modifications of multiple male genital structures using genomic introgression in Drosophila *

Evolution ◽  
2018 ◽  
Vol 72 (11) ◽  
pp. 2406-2418 ◽  
Author(s):  
Kentaro M. Tanaka ◽  
Yoshitaka Kamimura ◽  
Aya Takahashi
Author(s):  
F. Al-Bagdadi ◽  
D. Hoyt ◽  
P. Karns ◽  
G. Martin ◽  
M. Memon ◽  
...  

The most frequently occuring abnormality of the male genital system in mammals is the failure of one or both testes to descend into the scrotum. The reasons for abdominal or inguinal retention of testes could be anatomic malformation, faulty development or hormone imbalance.Cryptorchidism has been associated with either greatly reduced or absent spermatogenesis (Kaueakami et al, 1984), and being a source of neoplasia. According to Stick (1980), germinal carcinoma cells have been believed to be the cause of teratomas in equine cryptorchid testicles. Neoplasia has been reported in descended testes of unilateral cryptorchid patients (Martin et al, 1981).No distinction has been made in relating the problem of cryptorchid testes to inguinal or abdominal retention. The purpose of this study is to record the morphological differences between inguinal and abdominal cryptorchid testes as an aid in diagnosis and prognosis.


1970 ◽  
Vol 64 (3) ◽  
pp. 459-465 ◽  
Author(s):  
Ch. Owman ◽  
N.-O. Sjöberg ◽  
N. O. Sjöstrand ◽  
G. Swedin

ABSTRACT The effect of prolonged treatment with high doses of oestrogen and/or progesterone on the amount of adrenergic transmitter in the short adrenergic neurons of the male reproductive tract of castrated rats has been studied by chemical determinations and histochemical demonstration of noradrenaline. Oestrogen, progesterone, or a combination of both, had no overt effect on the total content or on the concentration of noradrenaline in the male genital organs. The results are discussed in the light of recent findings that the content of the noradrenaline transmitter in the short adrenergic neurons to the female genital tract is markedly influenced by these female sex hormones.


2018 ◽  
Author(s):  
Francisco Schneuer ◽  
Elizabeth Milne ◽  
Sarra E. Jamieson ◽  
Gavin Pereira ◽  
Michele Hansen ◽  
...  

Medicine ◽  
2019 ◽  
Vol 98 (11) ◽  
pp. e14843 ◽  
Author(s):  
Jigang Jing ◽  
Hua Zhuang ◽  
Yan Luo ◽  
Huijiao Chen ◽  
Yaping Rao
Keyword(s):  

2014 ◽  
Vol 35 (2) ◽  
pp. 415-453 ◽  
Author(s):  
Magdalena Błażewicz-Paszkowycz ◽  
Robert M. Jennings ◽  
Karen Jeskulke ◽  
Saskia Brix

AbstractIn Tanaidacea morphological identification of male individuals to the species level is complicated by two factors: the presence of multiple male stages/instars confuse the assessment of sexual stage while strong sexual dimorphism within several families obscures the morphological affinities of undescribed males to described females. Males of Paratanaoidea are often morphologically quite different from females and have not been discovered for most genera so far, which has led to the assumption that some tanaidaceans might have parthenogenetic reproduction or simply have undeveloped secondary sex traits. As a part ofthe IceAGE project (Icelandic marine Animals: Genetics and Ecology), with the support of molecular methods, the first evidence for the existence of highly dimorphic (swimming) males in four families of the superfamily Paratanaoidea (Agathotanaidae, Cryptocopidae, Akanthophoreidae, and Typhlotanaidae) is presented. This study suggests that these males might be the next instars after juvenile or preparatory males, which are morphologically similar to females. It has been assumed that “juvenile” males with a restricted ability for swimming (e.g., undeveloped pleopods) have matured testes, are capable of reproduction, and mate with females nearby, while swimming males can mate with distant females. Our explanation of the dimorphism in Tanaidomorpha lies in the fact that males of some species (e.g.,Nototanais) retain the same lifestyle or niche as the females, so secondary traits improve their ability to guard females and successfully mate. Males of other species that have moved into a regime (niche) different than that of the female have acquired complex morphological changes (e.g.,Typhlotanais).


2019 ◽  
Vol 116 (37) ◽  
pp. 18498-18506 ◽  
Author(s):  
Yoshitaka Fujihara ◽  
Taichi Noda ◽  
Kiyonori Kobayashi ◽  
Asami Oji ◽  
Sumire Kobayashi ◽  
...  

CRISPR/Cas9-mediated genome editing technology enables researchers to efficiently generate and analyze genetically modified animals. We have taken advantage of this game-changing technology to uncover essential factors for fertility. In this study, we generated knockouts (KOs) of multiple male reproductive organ-specific genes and performed phenotypic screening of these null mutant mice to attempt to identify proteins essential for male fertility. We focused on making large deletions (dels) within 2 gene clusters encoding cystatin (CST) and prostate and testis expressed (PATE) proteins and individual gene mutations in 2 other gene families encoding glycerophosphodiester phosphodiesterase domain (GDPD) containing and lymphocyte antigen 6 (Ly6)/Plaur domain (LYPD) containing proteins. These gene families were chosen because many of the genes demonstrate male reproductive tract-specific expression. AlthoughGdpd1andGdpd4mutant mice were fertile, disruptions ofCstandPategene clusters andLypd4resulted in male sterility or severe fertility defects secondary to impaired sperm migration through the oviduct. While absence of the epididymal protein families CST and PATE affect the localization of the sperm membrane protein A disintegrin and metallopeptidase domain 3 (ADAM3), the sperm acrosomal membrane protein LYPD4 regulates sperm fertilizing ability via an ADAM3-independent pathway. Thus, use of CRISPR/Cas9 technologies has allowed us to quickly rule in and rule out proteins required for male fertility and expand our list of male-specific proteins that function in sperm migration through the oviduct.


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