Abstract
Tardigrades are generally gonochoristic. Many moss-dwelling species propagate by parthenogenesis, but heterogony has not yet been found. Milnesium tardigradum, a carnivorous tardigrade, also has both sexes, but males are usually rare and many populations appear to have only parthenogenetic reproduction. Since 2000, I have maintained a thelytokous strain of Milnesium cf. tardigradum that originated from one female. Individuals of this strain were thought to be all females, but here I report that males have emerged in this strain at a very low frequency. This is the first report of the appearance of males in parthenogenetic tardigrades. On the first pair of legs of some individuals, I observed the modified claws characteristic of males of this species. It is unknown whether these males can actually function in sexual reproduction; however, they might allow some possibility of genetic exchange among clonal populations. No environmental factors that generate males were determined.
| Original language | English |
|---|---|
| Pages (from-to) | 849-853 |
| Number of pages | 5 |
| Journal | Zoological Science |
| Volume | 25 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2008 Aug |
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Keywords
- Parthenogenesis
- Sex ratio
- Sexual dimorphism
- Tardigrada
- Thelytoky
ASJC Scopus subject areas
- Animal Science and Zoology
Cite this
Appearance of males in a thelytokous strain of Milnesium cf. tardigradum (Tardigrada). / Suzuki, Atsushi C.
In: Zoological Science, Vol. 25, No. 8, 08.2008, p. 849-853.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Appearance of males in a thelytokous strain of Milnesium cf. tardigradum (Tardigrada)
AU - Suzuki, Atsushi C
PY - 2008/8
Y1 - 2008/8
N2 - Tardigrades are generally gonochoristic. Many moss-dwelling species propagate by parthenogenesis, but heterogony has not yet been found. Milnesium tardigradum, a carnivorous tardigrade, also has both sexes, but males are usually rare and many populations appear to have only parthenogenetic reproduction. Since 2000, I have maintained a thelytokous strain of Milnesium cf. tardigradum that originated from one female. Individuals of this strain were thought to be all females, but here I report that males have emerged in this strain at a very low frequency. This is the first report of the appearance of males in parthenogenetic tardigrades. On the first pair of legs of some individuals, I observed the modified claws characteristic of males of this species. It is unknown whether these males can actually function in sexual reproduction; however, they might allow some possibility of genetic exchange among clonal populations. No environmental factors that generate males were determined.
AB - Tardigrades are generally gonochoristic. Many moss-dwelling species propagate by parthenogenesis, but heterogony has not yet been found. Milnesium tardigradum, a carnivorous tardigrade, also has both sexes, but males are usually rare and many populations appear to have only parthenogenetic reproduction. Since 2000, I have maintained a thelytokous strain of Milnesium cf. tardigradum that originated from one female. Individuals of this strain were thought to be all females, but here I report that males have emerged in this strain at a very low frequency. This is the first report of the appearance of males in parthenogenetic tardigrades. On the first pair of legs of some individuals, I observed the modified claws characteristic of males of this species. It is unknown whether these males can actually function in sexual reproduction; however, they might allow some possibility of genetic exchange among clonal populations. No environmental factors that generate males were determined.
KW - Parthenogenesis
KW - Sex ratio
KW - Sexual dimorphism
KW - Tardigrada
KW - Thelytoky
UR - http://www.scopus.com/inward/record.url?scp=56649109825&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=56649109825&partnerID=8YFLogxK
U2 - 10.2108/zsj.25.849
DO - 10.2108/zsj.25.849
M3 - Article
C2 - 18795820
AN - SCOPUS:56649109825
VL - 25
SP - 849
EP - 853
JO - Zoological Science
JF - Zoological Science
SN - 0289-0003
IS - 8
ER -