Gynandromorphism in Crocothemis servilia

Gynandromorphism is the phenomenon that occurs when an individual organism possesses both

male Male (Planet symbols, symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or Egg cell, ovum, in the process of fertilisation. A male organism cannot sexual repro ...

and

female An organism's sex is female ( symbol: ♀) if it produces the ovum (egg cell), the type of gamete (sex cell) that fuses with the male gamete (sperm cell) during sexual reproduction. A female has larger gametes than a male. Females and ...

phenotypes In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological properti ...

due to

genetic chimera A genetic chimerism or chimera ( or ) is a single organism composed of cells of different genotypes. Animal chimeras can be produced by the fusion of two (or more) embryos. In plants and some animal chimeras, mosaicism involves distinct typ ...

of sex chromosomes in cells across the body and is most easily recognized in

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

that display

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

. An individual who displays this characteristic is called a gynandromorph. The term comes from the Greek γυνή (''gynē'') 'female', ἀνήρ (''anēr'') 'male', and μορφή (''morphē'') 'form', and is most commonly documented the field of

entomology Entomology (from Ancient Greek ἔντομον (''éntomon''), meaning "insect", and -logy from λόγος (''lógos''), meaning "study") is the branch of zoology that focuses on insects. Those who study entomology are known as entomologists. In ...

. The definition of “gynandromorphism” is distinct from both

intersexuality Intersex people are those born with any of several Sexual characteristics, sex characteristics, including chromosome patterns, gonads, or sex organ, genitals that, according to the Office of the United Nations High Commissioner for Human ...

and

hermaphroditism A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

, although they are sometimes used interchangeably.

Occurrence

Gynandromorphism has been noted in

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

(butterflies and moths) since the 1700s. It has also been observed in

crustaceans Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of Arthropod, arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquat ...

, such as

lobsters Lobsters are malacostracans decapod crustaceans of the family Nephropidae or its synonym Homaridae. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs have claws, in ...

and

crabs Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek), which typically have a very short projecting tail-like abdomen, usually hidden entirely under the thorax. Their exoskeleton is often thickened and ha ...

, in

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

tick Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...

flies Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...

locust Locusts (derived from the Latin ''locusta'', locust or lobster) are various species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstances they b ...

crickets Crickets are orthopteran insects which are related to bush crickets and more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 886 ...

dragonflies A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threate ...

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

termite Termites are a group of detritivore, detritophagous Eusociality, eusocial cockroaches which consume a variety of Detritus, decaying plant material, generally in the form of wood, Plant litter, leaf litter, and Humus, soil humus. They are dist ...

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamil ...

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s, and

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s. Although it can be seen in a variety of species, gynandromorphism is notably uncommon. Reporting depends on ease of detecting the phenomenon (whether a species displays noticeable sexual dimorphism) and how well-studied a region or organism is. For example, up until 2023 gynandromorphism had been reported in more than 40 bird species, but the vast majority of these are from the

Palearctic The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. Th ...

and

Nearctic The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface. The Nearctic realm covers most of North America, including Greenland, Central Florida, and the highlands of Mexico. The parts of North America ...

; meanwhile, incidents in species from other regions may go underreported due to lack of data collection.

Pattern of distribution of male and female tissues in a single organism

Several patterns of tissue distribution occur amongst observed gynandromorphs. Patch-like patterns may arise, but commonly the phenotype presents in a symmetrical pattern, of which there are three main types:

bilateral Bilateral may refer to any concept including two sides, in particular: *Bilateria, bilateral animals *Bilateralism, the political and cultural relations between two states *Bilateral, occurring on both sides of an organism ( Anatomical terms of l ...

, oblique, and transverse. Bilateral describes an organism that is split laterally with one side possessing female characteristics and the other having male characteristics. Oblique refers to a diagonal line across the

sagittal plane The sagittal plane (; also known as the longitudinal plane) is an anatomical plane that divides the body into right and left sections. It is perpendicular to the transverse and coronal planes. The plane may be in the center of the body and divi ...

that separates the male and female phenotypes. Lastly, transverse is a separation of male and female phenotypes along an axis that intersects with what would be considered the primary axis for the body of a given organism. A notable example in birds is the

zebra finch The zebra finches are two species of estrildid finch in the genus ''Taeniopygia'' found in Australia and Indonesia. They are seed-eaters that travel in large flocks. Species The species are: Previously, both species were classified as ...

. These birds have lateralized brain structures in the face of a common

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

signal, providing strong evidence for a non-hormonal primary sex mechanism regulating brain differentiation. Papilioandrogeusfemale.jpg, Normal female of '' Papilio androgeus'' Papilioandrogeusgynandromorph.jpg, Mosaic gynandromorph of ''Papilio androgeus'' Papilioandrogeosmale.jpg, Normal male of ''Papilio androgeus''

Causes

The exact cause for gynandromorphism is unknown, and appears to vary by species. One proposed cause for the phenotype in birds is a disruption that occurs in

meiosis Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one c ...

in female birds -- who possess ZW chromosomes -- in which

polar bodies A polar body is a small haploid cell that is formed at the same time as an egg cell during oogenesis, but generally does not have the ability to be fertilized. It is named from its polar position in the egg. When certain diploid cells in animal ...

are not forced out of the cell. This is then followed with

fertilization Fertilisation or fertilization (see American and British English spelling differences#-ise, -ize (-isation, -ization), spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give ...

by two Z-bearing

sperm cells A spermatozoon (; also spelled spermatozoön; : spermatozoa; ) is a motile sperm cell produced by male animals relying on internal fertilization. A spermatozoon is a moving form of the haploid cell that is the male gamete that joins with an ov ...

which creates cells in the embryo containing both ZZ and ZW chromosomes. The same phenomenon can be seen in other species, such as ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...

'', and creates a genetic mosaic which gives rise to the mixed phenotype.

As a research tool

Gynandromorphs occasionally afford a powerful tool in genetic, developmental, and behavioral analyses. In ''

'', for instance, they provided evidence that male courtship behavior originates in the brain, that males can distinguish conspecific females from males by the scent or some other characteristic of the posterior, dorsal,

integument In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, Exoskeleton, shell, germ or Peel (fruit), rind. Etymology The term is derived from ''integumentum'', which is Latin for "a coverin ...

of females, that the

germ cell A germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they unde ...

s originate in the posterior-most region of the blastoderm, and that somatic components of the gonads originate in the mesodermal region of the fourth and fifth abdominal segment.

References

External links

{{Commons category, Gynandromorphs
Stunning Dual-Sex Animals
at

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