Are Gonocytes stem cells?
Gonocytes are a transient population of male germ-line stem cells that are derived from primordial germ cells in the embryo and give rise to spermatogonial stem cells, which establish and maintain spermatogenesis in the postnatal testis.
What is Type A and Type B spermatogonia?
There are three types of spermatogonia – Type A (dark) which are reserve stem cells. Type A (pale) which are renewing stem cells. type B spermatogonia which are differentiating progenitors, and form spermatocytes.
What do primordial germ cells become?
After a period of mitotic proliferation, the primordial germ cells undergo meiosis and differentiate into mature gametes—either eggs or sperm. Later, the fusion of egg and sperm after mating initiates embryogenesis. The subsequent production in this embryo of new primordial germ cells begins the cycle again.
What is germ cell tumor?
Germ cell tumors are growths of cells that form from reproductive cells. The tumors may be cancerous or not cancerous. Most germ cell tumors occur in the testicles or the ovaries. Some germ cell tumors occur in other areas of the body, such as the abdomen, brain and chest, though it’s not clear why.
Where are germ cells?
Germ cells are cells that create reproductive cells called gametes. Germ cells are located only in the gonads and are called oogonia in females and spermatogonia in males. In females, they are found in the ovaries and in males, in the testes. During oogenesis, germ cells divide to produce ova, or eggs, in females.
Is spermatogenesis a sperm?
Spermatogenesis is the process of sperm cell development. Rounded immature sperm cells undergo successive mitotic and meiotic divisions (spermatocytogenesis) and a metamorphic change (spermiogenesis) to produce spermatozoa.
What is spermatogenesis and oogenesis?
Spermatogenesis and oogenesis are the processes of formation of male and female gametes. Spermatogenesis leads to the formation of sperms, whereas oogenesis helps in the formation of ova. The fertilization of sperm and ova leads to the formation of a zygote which further develops into an embryo.
Is seminoma benign or malignant?
A seminoma is a germ cell tumor of the testicle or, more rarely, the mediastinum or other extra-gonadal locations. It is a malignant neoplasm and is one of the most treatable and curable cancers, with a survival rate above 95% if discovered in early stages.
Where do primordial germ cells come from in humans?
Primordial germ cells originate in the endoderm of the yolk sac and migrate to the genital ridge to form the indifferent gonad. 46, XY and 46, XX gonads are initially indistinguishable. Indifferent gonads develop into testes if the embryo, or more specifically the gonadal stroma, is 46, XY.