Gynandromorph
Encyclopedia
Male
Male refers to the biological sex of an organism, or part of an organism, which produces small mobile gametes, called spermatozoa. Each spermatozoon can fuse with a larger female gamete or ovum, in the process of fertilization...
and female
Female
Female is the sex of an organism, or a part of an organism, which produces non-mobile ova .- Defining characteristics :The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon, is produced by the male...
characteristics. The term gynandromorph, from Greek "gyne" female and "andro" male, is mainly used in the field of Lepidopterology
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
(butterfly
Butterfly
A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...
/moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
study) or entomology
Entomology
Entomology is the scientific study of insects, a branch of arthropodology...
(all insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s). These characteristics can be seen in butterflies, where both male and female characteristics can be seen physically because of sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
. Cases of gynandromorphism have also been reported in crustaceans, especially lobsters, sometimes crabs and even in bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s. A clear example in birds is the gynandromorphic Zebra Finch. These birds have lateralised brain structures in the face of a common steroid signal, providing strong evidence for a non-hormonal primary sex mechanism regulating brain differentiation.
A gynandromorph can have bilateral asymmetry, one side female and one side male, or they can be mosaic
Mosaic (genetics)
In genetic medicine, a mosaic or mosaicism denotes the presence of two populations of cells with different genotypes in one individual who has developed from a single fertilized egg...
, a case in which the two sexes aren't defined as clearly.
Bilateral gynandromorphy arises very early in development, typically when the organism has between 8 and 64 cells. Later the gynandromorph is mosaic.
The cause of this phenomenon is typically, but not always, an abnormal event in mitosis during early development. While the organism is only a few cells large, one of the dividing cells fails to split its sex chromosomes correctly. This leads to one of the two cells having sex chromosomes that cause male development and the other cell having chromosomes that cause female development. For example, an XY cell undergoing mitosis duplicates its chromosomes, becoming XXYY. Normally this cell would divide into two XY cells, but in rare occasions the cell may divide into an X cell and an XYY cell. If this happens early in development, then a large portion of the cells are X and a large portion are XYY. Since X and XYY dictate different genders, the organism has a chunk of tissue that is female and another chunk that is male.
In his autobiography, Speak, Memory, the writer and lepidopterist
Lepidopterist
A lepidopterist is a person who specialises in the study of Lepidoptera, members of an order encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
Vladimir Nabokov
Vladimir Nabokov
Vladimir Vladimirovich Nabokov was a multilingual Russian novelist and short story writer. Nabokov wrote his first nine novels in Russian, then rose to international prominence as a master English prose stylist...
describes a beautiful gynandromorph butterfly, male on one side, female on the other, that he caught as a youth on his family's Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
n estate.
Chickens can also be gynandromorphous.
External links
- http://www.daltonstate.edu/galeps/Gynandromorphs.htm
- http://news.nationalgeographic.com/news/2005/06/0616_050616_gender_crab.html