Search results
Results from the WOW.Com Content Network
Zebrafish embryo 48 hours after fertilization. The arrows indicate four Rohon–Beard neurons. [1] Rohon–Beard cells are specialized primary neurons with mechanoreceptive properties. [2] [3] They occur during the embryonic stage of development and are found in the dorsal part of the spinal cord in fishes and amphibians.
This layer functions in protection by allowing the embryo to develop in a hypotonic solution so the cell will not burst. [5] Finally, the third set of blastomeres are the deep cells. These deep cells are located between the enveloping layer and the yolk syncytial layer and eventually give rise to the embryo proper.
The embryo during this process is called a gastrula. The germ layers are referred to as the ectoderm, mesoderm and endoderm. In diploblastic animals only the ectoderm and the endoderm are present. [8] * Among different animals, different combinations of the following processes occur to place the cells in the interior of the embryo:
The first ten weeks of gestational age is the period of embryogenesis and together with the first three weeks of prenatal development make up the first trimester of pregnancy. From the 10th week of gestation (8th week of development), the developing embryo is called a fetus.
Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. [1] [2] Sex determination is often distinct from sex differentiation; sex determination is the designation for the development stage towards either male or female, while sex differentiation is the pathway towards the development of the phenotype.
VE-cadherin is a classical cadherin from the cadherin superfamily and the gene is located in a six-cadherin cluster in a region on the long arm of chromosome 16 that is involved in loss of heterozygosity events in breast and prostate cancer.
At early presentation of pregnancy at around 6 weeks, early dating ultrasound scan may be offered to help confirm the gestational age of the embryo and check for a single or twin pregnancy, but such a scan is unable to detect common abnormalities. Details of prenatal screening and testing options may be provided.
The primitive streak is a structure that forms in the early embryo in amniotes. [1] In amphibians, the equivalent structure is the blastopore. [2] During early embryonic development, the embryonic disc becomes oval shaped, and then pear-shaped with the broad end towards the anterior, and the narrower region projected to the posterior.