Gonadolicious: A Review on Hermaphrodite Uterine and Vulval Development in C. elegans

1. Gonadolicious: A Review on Hermaphrodite Uterine and Vulval Development in C. elegans Jadine Paw April 8, 2005

2. Outline Basic introduction to anatomy Basics of Cell Lineage Germline Uterus Development Lineage Anatomy Vulva Development Lineage and anatomy

3. Introduction Symmetrical, bilobed joined at uterus Somatic gonad (DTC, sheath, sp, sp-ut valve, uterus and vulva) Germline (meiotic and mitotic zones)

4. Cell Lineage

5. D � all muscle cellsD � all muscle cells

6. Gonad Lineage At hatching: Germline from Z2 and Z3 (P4 lineage) Uterus and Vulva from Z1 and Z4 (MS) Vulva from Pn cells Note: gonads are all developed post-embryonically (L1-L4)

7. By the L2/L3 molt, there are12 descendents (Somatic Primordium) Relative cell positions in the adult -at hatching, the gonad primordium is in place with these 4 cells. -SS = spermatheca/sheath -DU = dorsal uterine -VU = ventral uterine-at hatching, the gonad primordium is in place with these 4 cells. -SS = spermatheca/sheath -DU = dorsal uterine -VU = ventral uterine

8. Distal Tip Cell and Tip

9. -single tip cell acts as a LEADER cell � -moves along body wall muscles and hypodermis � produces metalloproteases that remodel the basal lamina to help migraion -single tip cell acts as a LEADER cell � -moves along body wall muscles and hypodermis � produces metalloproteases that remodel the basal lamina to help migraion

10. Control mitosis/ meiosis Maintains close germcells in mitotic stage Expresses ligand LAG-2, germcells express receptor. Activation blocks meiotic entry -single tip cell -by default, cells enter mitosis when there is distance from the DTC. -if laser ablate, mitotic nuclei become meiotic and vice versa. -moves along body wall muscles and hypodermis � produces metalloprotease that remodel the basal lamina which facilitates migration --single tip cell -by default, cells enter mitosis when there is distance from the DTC. -if laser ablate, mitotic nuclei become meiotic and vice versa. -moves along body wall muscles and hypodermis � produces metalloprotease that remodel the basal lamina which facilitates migration -

11. Germline From Z2 and Z3 (P4 lineage) Both sperm and oocytes must be produced Sperm is made during L4, and then only oocytes are produced during adulthood

12. Germline & Distal Tip Mitotic zone Syncitium -incomplete borders with a central canal called the rachis (filled with RER, ribosomes, mitochondria) -20 cell diameters in length before hitting the transition zone-incomplete borders with a central canal called the rachis (filled with RER, ribosomes, mitochondria) -20 cell diameters in length before hitting the transition zone

13. Germline &Transition Zone Germ cells in early meiotic prophase Nuclei appear �crescent shaped� -prophase � replicated chromosomes condense and sister chromatids become visible. Spindle starts to assemble outside the nucleus.-prophase � replicated chromosomes condense and sister chromatids become visible. Spindle starts to assemble outside the nucleus.

14. Germline & Loop Diplotene stage Oocytes start single file Note: half of all oocytes are apoptotic, and most occur in this region Diplotene �The final stage of the first prophase of meiosis. All four chromatids of a tetrad are fully visible and homologous chromosomes start to move away from one another except at chiasmata.  cell corpses are engulfed by the sheath cells, which encompass most of the gonad. Diplotene �The final stage of the first prophase of meiosis. All four chromatids of a tetrad are fully visible and homologous chromosomes start to move away from one another except at chiasmata. cell corpses are engulfed by the sheath cells, which encompass most of the gonad.

15. Germline & Proximal Arm Arrest here at diakinesis Oocyte maturation (enlargement, cytoplasmic contents) until ready to be fertilized -such as RER, ribosomes, organelles -eggs enlarge to fill whole space in arm-such as RER, ribosomes, organelles -eggs enlarge to fill whole space in arm

17. Spermatheca 24 cells (from SS and DU) All sperm made in L4 Made in oviduct and pushed into spermatheca when 1st oocyte released Before oocyte passes, it is narrow and folded Made in L4 but not mature -before first ovulation, there is no sperm in spermatheca -potential for expansion � the lumen is made in L4 but it is not matured fully until the 1st oocyte passes through it. -before first ovulation, there is no sperm in spermatheca -potential for expansion � the lumen is made in L4 but it is not matured fully until the 1st oocyte passes through it.

19. -gonadal sheath � 0.4um thick, in a single layer. - 5 sheath cells/arm - promotes germline proliferation, oocyte mat, ovulation, engulfs germ cells that go through programmed cell death (not focused on because not the bulk of this talk)-gonadal sheath � 0.4um thick, in a single layer. - 5 sheath cells/arm - promotes germline proliferation, oocyte mat, ovulation, engulfs germ cells that go through programmed cell death (not focused on because not the bulk of this talk)

20. Uterus Development Begins in L2 By end of L4, development is complete Uterine cells clearest (embryos distort and crowd shape) -at the end of L4 may be the best time to examine the uterus (for research purposes) -can see how the embryos disrupt the shape of the uterus (and lumen)-at the end of L4 may be the best time to examine the uterus (for research purposes) -can see how the embryos disrupt the shape of the uterus (and lumen)

21. Uterus Anatomy -Uts are joined by adherens junctions-Uts are joined by adherens junctions

22. Uterus Anatomy Con�t� -Uts are joined by adherens junctions -utse stops it from prolapsing -Uts are joined by adherens junctions -utse stops it from prolapsing

23. Uterus Development

24. Uterus Cell Divisions

25. A Dorsal and Ventral Side AC � VERY important cell Ensures physical connection between uterus and vulva Also induces proper vulval AND uterine divisionsAC � VERY important cell Ensures physical connection between uterus and vulva Also induces proper vulval AND uterine divisions

26. -dorsal PI cells are larger than the ventral (like on next slide)-dorsal PI cells are larger than the ventral (like on next slide)

27. -cells in proper location/ shape doesn�t change much-cells in proper location/ shape doesn�t change much

28. - MIGRATION of the utse to position where ut2 is -vt4 and 8 become uv1- MIGRATION of the utse to position where ut2 is -vt4 and 8 become uv1

29. Taking Shape

30. -utse cells start to migrate outwards and attach to the seam cell. -mid L4 a fluid filled lumen begins to form between dorsal and ventral layers of uterus -6-7.5 hours into L4 all migrating nuclei have reached final location -uv and utse (pi cells) are the only ones that make contact with the vulva in anyway -can see here that the vulva has begun to ingress � vulval dev occurs at the same time. -utse cells start to migrate outwards and attach to the seam cell. -mid L4 a fluid filled lumen begins to form between dorsal and ventral layers of uterus -6-7.5 hours into L4 all migrating nuclei have reached final location -uv and utse (pi cells) are the only ones that make contact with the vulva in anyway -can see here that the vulva has begun to ingress � vulval dev occurs at the same time.

31. Final Development

32. Vulva Anatomy Made of 7 epithelial rings/ toroids Joined to each other via adherens junctions Each made of a tetranucleate syncitium or 2 binucleate half ring syncitia All progeny of ventral hypodermal cells Pn.p (born in L1) Same development time as uterus (L3 & L4) Require AC, like the uterus -white center- uterine cell connection-white center- uterine cell connection

33. Vulval Development Execution and Short-range Migration 22 epithelial cells made and migrate to make the 7 rings Cell fusions (during most of L4) 7 rings fuse Vulval muscles attach Eversion Vulva turns inside out (L4/ adult molt) Lumen closes to block transit of eggs

34. Vulva Cell Lineage

35. Vulva Cell Lineage -see here that these daughters, after TWO cell division are at the FINAL cells to make the 7 rings-see here that these daughters, after TWO cell division are at the FINAL cells to make the 7 rings

38. Short-Range Migrations A � 34 hrs, 22 vulval cells B � 35 hrs, vulD migrate to surround inner ring C � 36 hrs, outermost cells begin to send processes out D � 37 hrs, vulC fusion AC � black dot in middle

39. Lumen Formation Invagination 1� and some 2 � cells detach from cuticle and rearrange cell contacts Forms vulval lumen

40. Ring Fusions -if you laser ablate one side of the rings, the other side will migrate around, sometimes forming a complete ring-if you laser ablate one side of the rings, the other side will migrate around, sometimes forming a complete ring

41. Final Stage: Eversion