Sertoli cells secrete 

Androgenbinding protein (ABP), inhibin, and MIS

The fluid in the lumen of the seminiferous tubules is quite different from plasma; it contains very little protein and glucose but is rich in androgens, estrogens, K+ , inositol, glutamic and aspartic acids.  Maintenance of its composition depends on the blood–testis barrier.

#Id: 6778

#Unit 3. Fundamental Processes

The estimate is that as much as 70% of human genes produce antisense RNA.

#Id: 6779

#Unit 3. Fundamental Processes

Clustered Regularly Interspaced Short Palindromic Repeats CRISPR consist of repeated sequences (each 30 bp long and highly conserved within a given cluster) interleaved with spacer sequences of similar length but highly divergent sequence.

#Id: 6780

#Unit 3. Fundamental Processes

#Id: 6781

#Unit 3. Fundamental Processes

A set of conserved protein-coding genes is tightly associated with the CRISPR sequences. The two most highly conserved members (cas1 and cas2, for “CRISPR associated”) are found in all cases

#Id: 6782

#Unit 3. Fundamental Processes

The protospacer adjacent motif (or PAM for short) is a short DNA sequence (usually 2-6 base pairs in length) that follows the DNA region targeted for cleavage by the CRISPR system, such as CRISPR-Cas9. The PAM is required for a Cas nuclease to cut and is generally found 3-4 nucleotides downstream from the cut site

#Id: 6783

#Unit 3. Fundamental Processes

cas1, cas2, and cas4 required to create protospacer sequences Cas1 is  integrase, whereas Cas2 is a ribonuclease. In contrast, of other Cas proteins, Cas6 is involved in expression and processing of the CRISPR cluster and Cas3 in the interference of viral infection.