| First Author | Hogan BL | Year | 1987 |
| Journal | Mouse News Lett | Volume | 77 |
| Pages | 135-8 | Mgi Jnum | J:14117 |
| Mgi Id | MGI:62293 | Citation | Hogan BL, et al. (1987) Allelism of small eyes (Sey) with Dickie's small eye (Dey) on Chromosome 2. Mouse News Lett 77:135-8 |
| abstractText | Full text of MNL contribution: Research News: Allelism of Small eyes (Sey) with Dickie's small eye (Dey) on Chr 2. Sey is a homozygous lethal mutation affecting eye and nose development. It is allelic with seyH, a radiation-induced homozygous lethal mutation which has been mapped on Chr 2 proximal to pa and 25.8+/-3.5 cM from a (1). Recently, it was reported that Dickie's small eye (Dey), another homozygous lethal mutant affecting eye development (2), also maps proximal to pa with an RF of 25.8+/-3.3 with a (3). We have therefore tested for allelism between Sey and Dey by examining embryos resulting from the cross between Sey/+ females and a Dey/+ male (kindly provided by M. Davisson, Jackson Laboratory). The Sey/+ females were F1s from a cross between Sey/+ females from the stock being maintained at the NIMR and C3H/He males. The phenotypes of 138 implantation sites examined between 10.75 and 18.5d p.c. are given in Table 1. Of 117 informative embryos, 23% (27/117) showed no development of either the lens or nasal placodes. They resembled double mutant embryos from the cross Sey/+ x SeyH/+ (see, for example reference 1, Figure 5). 76% (90/117) showed development of lens and nose, but in about 1/3 (19/53) of the embryos aged 14.5 days or older, both eyes could be classified as colobomatous. Exencephaly was seen in a number of embryos, but there was no correlation with the Sey mutant phenotype. These results are compatible with the following: (a) Sey is allelic with Dey. We therefore propose that Dey be renamed SeyDey. (b) One of the heterozygotes (either Sey/+ or SeyDey/+) has colobomatous eyes (see below). (c) There is loss of both homozygous and heterozygous mutant embryos during development. Table 1. Phenotype of embryos from cross Sey/+ x Dey/+ Age: 10.75; Total sites: 13; Moles, v. retarded or dead: 2; Class 1*: 1; +Ex: 3; Class 2*: 7; +Ex: -; Age: 10.75; Total sites: 9; Moles, v. retarded or dead: 2; Class 1*: 2;+Ex: -; Class 2*: 5; +Ex: -; Age: 12.5; Total sites: 9; Moles, v. retarded or dead: -; Class 1*: 2; +Ex: -; Class 2*: 7; Age: 12.5; Total sites: 10; Moles, v. retarded or dead: 3; Class 1*: -; +Ex: -; Class 2*: 5; +Ex: 2; Age: 12.5; Total sites: 10; Moles, v. retarded or dead: 2; Class 1*: 1; +Ex: 2; Class 2*: 4; +Ex: 1; Age: 13.5; Total sites: 8; Moles, v. retarded or dead: -; Class 1*: -; +Ex: 3; Class 2*: 5; Age: 14.5; Total sites: 10; Moles, v. retarded or dead: 1; Class 1*: 4; +Ex: 1; Normal Eye: 2; Coloboma: 2; Age: 14.5; Total sites: 10; Normal Eye: 3; Coloboma: 7; Age: 14.5; Total sites: 8; Normal Eye: 8; Coloboma: -; Age: 14.5; Total sites: 7; Moles, v. retarded or dead: 3; Class 1*: 1; +Ex: -; Normal Eye: 1; Coloboma: 2; Age: 14.5; Total sites: 10; Moles, v. retarded or dead: 1; Class 1*: 2; +Ex: -; Normal Eye: 4; Coloboma: 3; Age: 16.5; Total sites: 10; Moles, v. retarded or dead: 3; Class 1*: 2; +Ex: -; Normal Eye: 5; Coloboma: -; Age: 16.5; Total sites: 8; Moles, v. retarded or dead: 2; Class 1*: -; +Ex: -; Normal Eye: 3; Coloboma: 3; Age: 16.5; Total sites: 8; Moles, v. retarded or dead: -; Class 1*: 1; +Ex: -; Normal Eye: 4; Coloboma: 2; +Ex: 1(Embryo dying); Age: 18.5; Total sites: 8; Moles, v. retarded or dead: 2; Class 1*: 2; +Ex: -; Normal Eye: 4; Coloboma: -; Total: 138; Moles, v. retarded or dead: 21; Class 1*: 27; Class2*/Normal Eye: 34; Class 2*: Coloboma: 19; 90. Age of embryos. Noon on day of plug is 0.5 days post coitum *Class 1 Embryos without lens or nasal pit or eyes and nose *Class 2 Embryos with lens and nasal pit or eyes and nose Exencephaly Embryo dying Control crosses were then carried out between the same SeyDey/+ male and inbred C3H/He females. The results are shown in Table 2. These results show clearly that SeyDey/+ heterozygotes develop colobomatous eyes. On average these embryos were also 13% smaller than their litter mates from measurements of crown-rump length. There is also evidence for prenatal death of heterozygotes. No exencephaly was seen. Table 2. Phenotype of embryos from cross +/+ x Dey/+ Age: 14.5; Total sites: 11; Moles or v. retarded: 2; Dead (approx. age): -; Normal eyes: 5; Colobomatous eyes: 4; Age: 14.5; Total sites: 9; Moles or v. retarded: 2; Dead (approx. age): -; Normal eyes: 5; Colobomatous eyes: 2; Age: 15.5; Total sites: 9; Moles or v. retarded: 1; Dead (approx. age): 1 (~11d); Normal eyes: 6; Colobomatous eyes: 1; Age: 16.5; Total sites: 6; Moles or v. retarded: -; Dead (approx. age): 1 (~12.5d); Normal eyes: 1; Colobomatous eyes: 4; Age: 16.5; Total sites: 8; Moles or v. retarded: -; Dead (approx. age): -; Normal eyes: 6; Colobomatous eyes: 2; Age: 17.5; Total sites: 7; Moles or v. retarded: -; Dead (approx. age): 2 (~13.5d); Normal eyes: 3; Colobomatous eyes: 2; Age: 17.5; Total sites: 8; Moles or v. retarded: 2; Dead (approx. age): -; Normal eyes: 1; Colobomatous eyes: 5; Age: 18.5; Total sites: 9; Moles or v. retarded: 1; Dead (approx. age): 1 (~17.5d); Normal eyes: 5; Colobomatous eyes: 2; Age: 18.5; Total sites: 9; Moles or v. retarded: 5; Dead (approx. age): -; Normal eyes: 2; Colobomatous eyes: 2; Total: 76; Moles or v. retarded: 13; Dead (approx. age): 5; Normal eyes: 34; Colobomatous eyes: 24 On the basis of these and earlier findings (1) we suggest that SeyH and SeyDey are deletions at and around the Sey locus, while Sey may be a smaller deletion or point mutation. Brigid Hogan and Colin Hetherington with Mary Lyon (MRC Radiobiology Unit, Chilton) References: 1. B.L.M. Hogan et al. (1986). J. Embryol. Exp. Morph. 97, 95-110. 2. K. Theiler et al. (1978). Anat. Embryol. 155, 81-86. 3. M. Davisson (1986). Mouse News Letter No. 75, 30-31. |
