Biology, asked by Rkaran3408, 8 months ago

Mention the difference between male germ cells and sertoli cells?

Answers

Answered by thankyebo12
0

Answer:

germ cells and sertoli cells?

Explanation:

SERTOLI CELLS ARE REQUIRED FOR GERM CELL

DEVELOPMENT

The descriptive morphology has been informative, and

these morphological data coupled with some endocrine

physiology have led to an important and apparently simple

axiom; i.e., spermatogenesis in higher vertebrates is dependent on the functions of Sertoli cells. The concept of a

basic requirement for Sertoli cells is most strongly supported by two important sets of experimental findings. First,

the endocrine regulation of spermatogenesis is a result of

hormone action on Sertoli cells (for a review see [14]). Second, the function and efficiency of Sertoli cells appear to

be limiting to germ cell numbers. Evidence for and challenges to these findings are discussed below.

Our current understanding of the primary endocrine

regulation of spermatogenesis is outlined in Figure 1. Few

investigators would question the roles of FSH and testosterone as the primary regulators of spermatogenesis. There

is still considerable discussion about the relative importance of FSH in the fully adult male nonseasonal breeding

rodent [15]. In some of these rodent species, the role of

FSH in the prepubertal animal appears to be transferred to

testosterone in the adult. The fundamental notions that FSH

is rk of

a need for an androgen receptor in germ cells. Second, the

common vole lacks the X-chromosome in all spermatogonia or advanced germ cells. It follows that spermatogenesis

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critical biological importance must deal with the contrary

genes from

studies on three interesting animal models in which the

size of the testis and the spermatogenic output was manipulated by changing the number of Sertoli cells. First, Orth

et al. [27] inhibited the proliferation of Sertoli cells during

testicular development and produced rats with smaller testes.

Second, propylthiouracil was used to inhibit thyroid hormone action during development, and this treatment resulted in rats with larger than normal testes [28]. Third,

hemicastration of developing boars at the appropriate age

resulted in increased proliferation of Sertoli cells and larger

than normal testes [29]. In all three of these animal models,

the ratio of spermatids to Sertoli cells remained relatively

constant. The obvious conclusion is that the number of germ

cells appears to be directly related to the number of Sertoli

cells and probably to their synthetic capability.

THE FUNCTION OF SERTOLI CELLS

What do Sertoli cells do that makes them necessary for

germ cell development in higher vertebrates? What is their

role in spermatogenesis? It appears that during development Sertoli cells play a role in the formation of the testis

[30]. This developmental role is currently under investigation and probably involves the expression of a number of

The general experimental approach to identify these

specific products made by Sertoli cells has been to isolate

and characterize the products present in cultured Sertoli

cells or in the spent medium of cultured Sertoli cells. More

recently, the availability of numerous antisera and cDNA

probes has allowed for quick screens of histological sections using immunohistochemistry and/or in situ hybridization. Additional factors continue to be added to the catalog of potentially important products of Sertoli cells, but

information about the identity of these products has not

often provided insight into their biological functions. There

has also been a tendency to extrapolate results from the

tt Adluminal Compartment

and proteases and protease inhibitors. Secretion may occur specifically to

the adluminal or basal compartment or to both. The type, amount, and

direction of secretion may be influenced by stage of testicular development, endocrine status of animal, and stage of cycle of seminiferous epithelium.

culture system directly to a Sertoli cell function without

testing the extrapolation in vivo. The concept that Sertoli

cells metabolize glucose to lactate and pyruvate as a form

of pre-digestion for the eventual use by germ cells arose

because of the capability of cultured Sertoli cells to produce lactate and the inefficient use of glucose by cultured

germ cells [33-38]. However, many types of cells in culture

produce lactate, some produce more than do Sertoli cells,

and direct proof of this potentially important physiological

event is lacking and experimentally difficult to obtain [39].

Sertoli cells dedicate a reasonably large percentage of

their protein synthesis to the synthesis and secretion of glycoproteins [40]. The glycoproteins secreted by the Sertoli

cells can be placed in several categories according to their

known biochemical properties (Fig. 2). The first category

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