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Vol. 45 No. 1, 2006
Sex Identification of the Black-faced Spoonbill (Platalea minor)
Yeong-Hsiang Cheng1, Tzong-Fu Kuo2, Der-Nan Lee1, and Ching-Feng Weng3,*
1Department of Animal Science, National I-Lan University, Ilan, Taiwan 260
2Department of Veterinary Medicine, National Taiwan University, Taipei, Taiwan 106
3Institute of Biotechnology, National Dong-Hwa University, Hualien, Taiwan 974
Yeong-Hsiang Cheng, Tzong-Fu Kuo, Der-Nan Lee, and Ching-Feng Weng (2006) The Black-faced Spoonbill (BFS), Platalea minor,
endemic to East Asia, is a well-known species listed as globally
“critically endangered”. It is difficult to recognize the gender of a
BFS by its appearance; this can make it extremely difficult to
implement human-assisted breeding programs, as well as evolutionary and
ecological studies. In this work, therefore, a molecular approach was
used to determine the sex of the endangered monomorphic BFS, as opposed
to a morphological or histological approach. In Dec. 2002, an outbreak
of Clostridium botulinum
toxin type C killed many birds overwintering in the Tseng-Wen estuary,
southwestern Taiwan, and this provided the opportunity to obtain muscle
samples for DNA extraction. The polymerase chain reaction (PCR) with a
single set of primers was employed to amplify a fragment in both the
chromobox-helicase-DNA-binding genes (CHD)-W and CHD-Z; after
electrophoresis, the products showed a single band in males, with
females having a 2nd distinctive band. The PCR products for the CHD-Z
and -W genes were 658 and 464 bp, respectively. The nucleotide
sequences of these bands were further confirmed after cloning and
sequencing. The nucleotide sequences of the CHD-Z and -W genes were 83%
homologous. When using morphological and histological examination
results for comparison, 26 birds (14 males and 12 females; sex ratio,
1.16) were correctly sexed using our test. This study is the first time
that the gender of the Black-faced Spoonbill has been identified using
the PCR technique; there is great potential for applying this tool for
further investigations into the ecology and reproductive behavior of
this species.
Key words: Sex ratio, Chromobox-helicase-DNA-binding gene, Black-faced Spoonbill, Platalea minor, PCR.
*Correspondence: Tel: 886-3-8633637. Fax: 886-3-8630255. E-mail: cfweng@mail.ndhu.edu.tw
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