Worm Breeder's Gazette 1(2): 20
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
In Volume 1 #1 of the newsletter an autosomal temperature-sensitive sterile mutation (TS17) was reported to have sexually dimorphic phenotype: spermatogenesis defect in hemaphrodites and intersexuality in 'males'. Further mapping of this mutation by Ken Lew and Johji Miwa has located TS17 in linkage group IV. The second allele of this gene is also linked to IV. Therefore, the intersex gene is distinct from either of the two known transformer genes. Observation of Feulgen stained mutant worms shows that TS17 hermaphrodites grown at 25 C are totally devoid of spermatocytes and mature sperm. At the time of normal spermatogenesis gonadial cells in the position of normal spermatocytes begin to mature in the pattern characteristic of oocytes. These oocytes can be fertilized by outcross sperm, but in the absence of mating they pass through the empty spermatheca and undergo endoduplication of their DNA becoming highly polyploid. These polyploid oocytes are laid as 'squashy eggs'. TS17 intersexes are variable in morphology. They always have a normal-looking bursa and nearly always contain mature oocytes. However, the vulva is not always present and when present is often abnormal so that matings of intersexes to males have not yet been successful. Consequently we do not know whether the intersex oocytes are functional. The intersex gonads vary from normal hermaphrodite shape to male configuration. Occasionally they contain sperm. Often the gonad is broken up into lumps packed solid with nuclei, or it loops around in odd patterns and may contain highly polyploid cells distinct from polyploid oocytes. For analyzing morphology I recommend the use of a camera lucida with stained preparations. Feulgen is already in wide use amongst worm breeders and Hematoxylin/eosin or toluidine blue complements Feulgen by providing information about cytoplasm and nucleoli.