Zauner et al. 10.1073/pnas.0610799104. |
Fig. 4. Vulva development in P. pacificus and C. elegans. (a) In C. elegans, the vulva equivalence group comprises six cells, P(3-8).p. P(1,2,9-11).p fuse with the hypodermis early in development. P(5-7).p are induced to give rise to vulva tissue by a signal from a single cell (the "anchor cell" of the somatic gonad). (b) In P. pacificus, P(1-4).p and P(9-11).p die early in development by programmed cell death. Thus, the vulva equivalence group consists of only four cells. P(5-7).p are induced to differentiate by a continuous signal from multiple cells of the somatic gonad. P8.p, the only surviving VPC that does not differentiate, remains epidermal and has novel properties.
Fig. 5. Construction of recombinant inbred lines. Two polymorphic strains, RS106 and PS1843, are crossed, and single larvae are transferred to new plates for at least nine generations. The resulting recombinant inbred lines (RIL) are homozygous at nearly all loci. Each RIL carries a unique combination of maternal and paternal loci. Selected RILs are used to raise second- and third-generation RILs.
Fig. 6. Genotyping of RIL A8BC7. Marks indicate approximate genetic positions of SNP markers one the six chromosomes of P. pacificus used to genotype RIL A8BC7. This RIL shows transgression in respect to LI as well as P8.p competence after ablation of P(5-7).p. Most of the loci in that particular RIL display the RS106 genotype, except a large region on chromosome I and some markers on chromosomes V and X which stem from the PS1843 (Washington, "W") background.
Fig. 7. Six of seven third-generation RILs that show P8.p competence after ablation of P(5-7).p retain a large region of PS1843 origin on Chromosome I.