Présence dans une population congolaise deMus (Leggada) triton Th. de femelles hétérozygotes pour une délétion caractérisée par la suppression du bras court de l'un des chromosomes X métacentriques

Abstract

A sample of 12Mus (Leggada) triton Th. from the region of Bukavu (Democratic Republic of Congo) contains 5 ♂♂ and 7 ♀♀. 2N=32. All the autosomes are acrocentric. The sex-chromosomes of the ♂ are of the typeX—Y, theX beeing a big submetacentric (I.C.=0,4). Three ♀♀ possess two metacentricX, as expected. By four ♀♀, there is only one typicalX whose partner is acrocentric and as long as the long arm of a normalX. ThisX must have been arisen through the deletion of the short arm and is calledX _ddc.

The statistical analysis of the sample is compatible with this pattern:

$$\begin{array}{*{20}c} { \circ \circ } \\ { + + } \\ \end{array} \begin{array}{*{20}c} {X---X = 4/9} \\ {X---X_{dc} = 4/9} \\ {X_{dc} ---X_{dc} = 1/9} \\ \end{array} \begin{array}{*{20}c} { \nearrow \nearrow } \\ { \circ \circ } \\ \end{array} \begin{array}{*{20}c} {X---Y = 2/3} \\ {X_{dc} ---Y = 1/3} \\ \end{array} $$

It means that the typesX _dc−X_dc andX _dc−Y must be present in the population.