14. Genetic Control of Development
Developmental Patterning Genes
31PRACTICE PROBLEM
During vulva formation in Caenorhabditis elegans, interaction between two neighboring cells, Z1.ppp and Z4.aaa, determines which will become the gonadal anchor cell (from which the vulva forms) and which will become a precursor to the uterus. The lag-2 gene encodes the Notch signal protein, and lin-12 gene encodes the Notch receptor protein. By chance, one cell ends up secreting more of the LAG-2 protein than the other cell, which causes the neighboring cell to increase production of the LIN-12 protein. The expression of lin-12 directs selection of the uterine pathway. What will the phenotype of homozygous recessive lin-12 mutants be?
During vulva formation in Caenorhabditis elegans, interaction between two neighboring cells, Z1.ppp and Z4.aaa, determines which will become the gonadal anchor cell (from which the vulva forms) and which will become a precursor to the uterus. The lag-2 gene encodes the Notch signal protein, and lin-12 gene encodes the Notch receptor protein. By chance, one cell ends up secreting more of the LAG-2 protein than the other cell, which causes the neighboring cell to increase production of the LIN-12 protein. The expression of lin-12 directs selection of the uterine pathway. What will the phenotype of homozygous recessive lin-12 mutants be?