Metafemale Explained

A metafemale (or superfemale) is a low viability Drosophila fruit fly with a female phenotype in which the ratio of X chromosomes to sets of autosomes (A) exceeds 1.0.^[1] For example: a fly with one X chromosome and two sets of autosomes is a normal male, a fly with two X chromosomes and two sets of autosomes is a normal female, and a fly with three X chromosomes and two sets of autosomes (or four X chromosomes and three sets of autosomes) is a metafemale.

American geneticist Calvin Bridges, who discovered the genic balance sex-determination system in Drosophila in 1921, used the terms "superfemale" and "supermale".^[2] German-American geneticist Curt Stern proposed the alternative terms "metafemale" and "metamale" in 1959.^[3]

External links

• Book: Gilbert, Scott F.. 2000. Chapter 17. Sex determination. Developmental biology. Sunderland, Mass.. Sinauer Associates. 9780878932436. registration.

Chromosomal Sex Determination in Mammals. Bethesda, Md.: National Center for Biotechnology Information.Chromosomal Sex Determination in Drosophila. Bethesda, Md.: National Center for Biotechnology Information.

Notes and References

1. Book: King. Robert C.. Mulligan. Pamela Khipple. Stansfield. William D.. 2013. A dictionary of genetics. 8th. Oxford. Oxford University Press. 978-0-19-976643-7. 189, 288, 458.
   genic balance: a mechanism of sex determination, originally discovered in Drosophila, that depends on the ratio of X chromosomes to sets of autosomes (A). Males develop when the X/A ratio is 0.5 or less, females develop when the X/A ratio is 1.0 or greater, an intersex develops when the ratio is between 0.5 and 1.0. See Appendix C, 1925, Bridges; metafemales, metamales, sex determination.
   metafemale: in Drosophila, a female phenotype of relatively low viability in which the ratio of X chromosomes to sets of autosomes exceeds 1.0, previously called a superfemale. See intersex, metamale.
   metamale: in Drosophila, a poorly viabile male characterized by cells containing one X and three sets of autosomes, previously called a supermale. See intersex, metafemale.
   superfemale: metafemale (q.v.).
   supermale: metamale (q.v.).
2. Bridges. Calvin B.. September 16, 1921. Triploid intersexes in Drosophila melanogaster. Science. 54. 1394. 252–254. 10.1126/science.54.1394.252. 17769897. 1646022.
3. Stern. Curt. December 12, 1959. Use of the term 'superfemale'. Lancet. 274. 7111. 1088. 10.1016/S0140-6736(59)91557-0.