PMID: 1202928Sep 1, 1975Paper

Development of the gonads and gonaducts in the polypterids (Pisces)

Acta Zoologica Et Pathologica Antverpiensia
W M De Smet

Abstract

No study of the development of the gonads and gonoducts in Polypterus has ever been made in a more or less complete way. The present study does not fill up this gap, but repairs several lacks of knowledge, by putting clear a few items that may contribute to a better understanding of this development. In larvae between 5,5 mm and 9,6 mm the primary gonocytes appear under the pronephric ducts in the anterior region of the opisthonephros. A genital crest is foreshadowed there; one of its characteristics is a cubial epithelium. The latter does not have any relation with peritoneal channels and it does not contribute to the formation of gonocytes. In the following stages the gonocytes get very numerous because of cellular multiplication. They cause a local transformation of the genital crest into a genital fold; when the number of gonocytes has increased very much, a part of the fold gets transformated into a gonad. At no stage is there any intrusion of medullary tissue into this gonad anlage.

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.

© 2022 Meta ULC. All rights reserved