In biology, a klepton (abbreviated kl.) and synklepton (abbreviated sk.) is a

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 requires input from another biological

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

(normally from a species which is closely related to the kleptonic species) to complete its reproductive cycle. Specific types of kleptons are ''zygokleptons'', which reproduce by zygogenesis; ''gynokleptons'' which reproduce by gynogenesis, and ''tychokleptons'', which reproduce by a combination of both systems. Kleptogenic reproduction results in three potential outcomes: * A unisexual female may simply activate

cell division Cell division is the process by which a parent cell (biology), cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukar ...

in the egg through the presence of a male's

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

without incorporating any of his

genetic material Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic aci ...

—this results in the production of clonal offspring. * The female may also incorporate the male's sperm into her

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

, but can do so without excising any of her genetic material. This results in increased

ploidy Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

levels that range from

triploid Polyploidy is a condition in which the cells of an organism have more than two paired sets of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one fro ...

pentaploid Polyploidy is a condition in which the biological cell, cells of an organism have more than two paired sets of (Homologous chromosome, homologous) chromosomes. Most species whose cells have Cell nucleus, nuclei (eukaryotes) are diploid, meaning ...

in wild individuals. * Finally, the female also has the option of replacing some of her genetic material with that of the male's, resulting in a "hybrid" of sorts without increasing ploidy.

Etymology

The term is derived from the (Ancient or Modern)

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

+ -on, after

, or , 'to steal'. A klepton "steals" from an exemplar of another species in order to reproduce. In a paper entitled "Taxonomy of Parthenogenetic Species of Hybrid Origin", Charles J. Cole argues that the thief motif closely parallels the behaviour of certain reptiles.

Examples

Salamander species

In the wild, five species of '' Ambystoma'' salamanders contribute to a unisexual complex that reproduces via a combination of gynogenesis and kleptogenesis: ''A. tigrinum'', ''A. barbouri'', ''A. texanum'', ''A. jeffersonium'', and ''A. laterale''. Over twenty genomic combinations have been found in nature, ranging from "LLJ" individuals (two ''A. laterale'' and an ''A. jeffersonium'' genome) to "LJTi" individuals (an ''A. laterale'', ''A. jeffersonium'', and an ''A. tigrinum'' genome). Every combination, however, contains the genetic information from the ''A. laterale'' species, and analysis of mitochondrial DNA has indicated that these unisexual species most likely diverged from an ''A. barbouri'' individual some 5million years ago, making them the oldest known unisexual vertebrate species. The fact that these salamanders have persisted for so long is remarkable, as it contradicts the notion that a majority of asexual lineages arise when the conditions are right and quickly disappear. It has been argued that this persistence is very much due to the aforementioned "genome replacement" strategy that accompanies kleptogenic reproduction—replacing a portion of the maternal genome with paternal DNA in offspring has allowed unisexual individuals to "refresh" their genetic material through time. This facet of kleptogenesis was recently ascertained from genetic research that indicates there is no ancestral ''A. laterale'' genome that is maintained from one unisexual to the next, and that there is not a specific "L" genome that is found more often than others. "L" genetic material found in these salamanders has also not evolved to be substantially unique from sexual genomes. In 2007 Bogart et al found that, within a population, unisexual and sexual individuals are able to co-exist; that the genetic makeup of the unisexuals is highly variable; and that unisexual individuals share

alleles An allele is a variant of the sequence of nucleotides at a particular location, or locus, on a DNA molecule. Alleles can differ at a single position through single nucleotide polymorphisms (SNP), but they can also have insertions and deletions ...

with sexual individuals.

Frog species

Other species exhibiting the property include European water frogs of the genus ''

Pelophylax ''Pelophylax'' is a genus of true frogs widespread in Eurasia, with a few species ranging into northern Africa. This genus was erected by Leopold Fitzinger in 1843 to accommodate the green frogs of the Old World, which he considered distinct fro ...

''.

Fish species

The Amazon Molly ''( Poecilia formosa)'' exhibits gynogenesis.

References