Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
23 Cards in this Set
- Front
- Back
|
Doublesex determination |
XX prevails - sex lethal is on and splices doublesex - female traits aoutosomal prevails - sex lethal is repressed and splices male doublesex - male traits DsxM/F |
|
|
sex lethal |
sex lethal induces transformer tra and tra2 protein activity which splice doublesex in female DsxF acts with intersex to make transcription factor for femininity No tra in male dsxM - acts alone as a transcription factor |
|
|
Sex specific behaviors in drosophila |
Fruitless gene tra and tra2 splice fruitless - no behavior Fruitless induces male behavior |
|
|
Gametogenesis PGS - primordal germ cells |
1. form germ plasm and determination of PGCs 2. PGCs migrate to gonads 3. Meiosis - sperm and egg 4. Differentiation of sperm and egg 5. Hormonal control of gamete maturation and ovulation |
|
|
Aoutonomous specification |
cytoplasmic determinants (germ plasm) flies/ frogs still not known what half germ plasm does maybe acts as a transcription/translation inhibitor (prevents cells from becoming anything else) |
|
|
Conditional specification |
specified by neighbouring cells salamanders and mammals |
|
|
Namatode germ cell specification |
differential cleavage divides animal and vegetal chromosomes intact only in pri germ cells animal pole: chromosome diminution vegetal pole: germ plasm allows chromosomes to remain normal |
|
|
Drosophila pole plasm |
PGCs form as a group in posterior germ cell less comes from nurse cells and is found in the pole plasm gcl prevents gene transcription in future pole cells |
|
|
cytocyte formation |
Germ cells form stem cell and cytoblast cytoblast divides and becomes 16 cytocytes connected by ring canals C1 - oocyte, others become nurse cells |
|
|
Gsl oskar nanos vasa piwi/aubergine |
selectively prevents transcription germ cell formation inhibits translation of some mRNAs germ cell differentiation and meiosis transcription repressors |
|
|
Polar granules component protein PGC |
prevents expression of somatic genes in pole cells |
|
|
Germ cell determination in frogs |
vegetal - kinesin and microtubules - localization Cleavage - germ plasm is brought up in yolk, associates with endoderm, migrates to genital ridges Guided by fibronectin PCGs divide three times while migrating - 30 colonize gonads |
|
|
Germ cell formation and migration in males |
Induced germ cells form at epiblast - primitive streak and allantois BMP4 and BMP8 from extraembryonic mesoderm induces cluster to become germ cells these migrate out of primitive streak into endoderm - fragilis, blimp, stella |
|
|
fragilis blim1 stella |
expressed in PGCs and somatic cells (competent) transcription inhibitor - these cells are restricted to germ cell fate ( specification/differentiation) germ cell fate only (differentiation) |
|
|
PGC migration |
cells migrate over substrate by extension of filopodia Genital ridges secrete fibronectin, sdf1 sdf1 binds to PGC Pgcs are surrounded by cells that form a traveling niche |
|
|
Meiosis |
pgc in gonad divide before reducing two cell divisions, no dna replication, pair and recombine M1 seperates chromosomes M2 seperates sister chromatids |
|
|
What is different between female meiosis and male meiosis |
pattern of DNA methylation and RA concentration |
|
|
RA and meiosis |
RA is produced by mesonephric kidney - initiations meiosis males degrade RA |
|
|
oogenesis vs spermatogenesis |
PGCs generate sperm -wnt signaling promotes proliferation spermatogonia secrete BMP8b, regulates spermatogenesis during puberty |
|
|
Primary spermatocytes secondary spermatocytes, spermatids, sperm cells |
2n n |
|
|
steroli cells nourish and protect developing sperm cells |
spermatogenic germ cells bind to steroli by -Ncadherin -galactosyltransferase molecules |
|
|
GDNF role |
steroli secretes GDNF and SCF - regulated by FSH GDNF level determine whether cells differentiate into spermatocytes or remain spermatogonia |
|
|
FSH |
connects endocrine and sertoli cells to control sperm level syncytium communicates through spermatogonial division specialized gene expression |
