Worm Breeder's Gazette 12(5): 87 (February 1, 1993)

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.

Alignment of the Physical and Genetic Maps in the dpy-14 Region

Sheldon McKay, Ann Rose

Department of Medical Genetics, University of British Columbia, Vancouver, CA

hDÄ8 was identified as a gamma radiation induced lethal allele that failed to complement dpy-14 ,which is in the LGI central gene cluster. The right breakpoint lies just to the right of dpy -14, between let-86 and let-389 and has been assigned to the cosmid clone, C14A12 .Since the region near the right breakpoint has been intensively studied both genetically and physically (McKim, Starr and Rose MGG 233: 1992; Prasad, Starr and Rose, Genome 36: 1993) we decided to undertake a high resolution alignment of the genetic and physical maps over a small, well defined interval.

Five overlapping cosmids, K01B11 , C37A2 , E02D9 , T14D10 and T21G5 ,which are anchored to the genetic map near the right breakpoint of hDÄ8 by sP1 and dpy- 14, were used to create transgenic strains. Individual cosmids were coinjected with pRF4 using the method of Mello et al. (EMBO 10(12): 1991). In cases where the cosmid clone was in a lorist vector, a construct consisting of a KanR cassette (GenBlock-Pharmacia) inserted into the pUC18 cloning site was included in the injection mixture to facilitate homologous recombination between pRF4 and the cosmid. The presence of Lorist cosmids in transgenic worms was verified by PCR analysis using primers specific to Lorist vector sequence. The Extrachromosomal arrays containing the cosmids were crossed out of the canonical transgenic line and used to do complementation analysis with lethal alleles that map inside of hDÄ8 near the right breakpoint. We have tested alleles of 13 essential genes, let-543 , let-521 , let-399 , let-394 , let-385 , let-397 , let-398 , let-529 , let-534 , let-544 , let-545 , let-605 and let-86 :

let-398 ( h257 )normally arrests development as an L2 larva. The cosmid K0B11 allows it develop adulthood and lay eggs which do not hatch. Iet-534 ( h260 ), let-394 ( h262 )and dpy-14 ( el88 )are rescued by T14D10 . Iet-545 ( h842 ), let-534 ( h260 )and let-394 ( h262 )are rescued by T21G5 ,indicating that the this clone overlaps with T14D10 by at least two genes.

[See Figure]