Date: 04/08/2009
Category: Natural resources and environment
Contact: Astrid Vargas
Telephone: (+34) 959 051 072
Email: lynexexsitu@lynexexsitu.es
With this technique, that complements the most used one -the analysis of hormones found in faeces-, researchers have got to know the most reliable way to chemically detect the hormone relaxine, which is naturally produced by the placenta and ovaries of all mammals during the pregnancy.
For Astrid Vargas, manager of the breeding program and head of El Acebuche Breeding Centre (located in Doñana, Huelva), the procedures used before did not follow a common pattern in these felines, ‘so we wanted to check if the urine could be used as an alternative more reliable method for the diagnosis’ .
The relevance of the work carried out by Astrid Vargas and Katarina Jewgenow consists of designing ‘exact methods’ to take urine and plasma samples as well as setting the right time to carry out the test. The perfectioning of this pregnancy test results in new appropriate tools being provided to make sure that the means used for the captive breeding of the unique Iberian lynx are more effective.
’We have been able to develop the method for blood sample taking, which is the most complicated one, in collaboration with our colleagues from the German Institute; we have also designed proper recipients for such sample taking both of blood and urine of lynx females’ Astrid Vargas points out. The researchers from the Institute for Zoo and Wildlife Research (IZW, Berlin) are a worldwide reference in the reproduction of Lynx lynx.
A natural ‘bat’
In order to take samples, researchers have worked with a special collaborator: a bloodsucking insect of the species called dipetalogaster (Triatomines), which makes blood and therefore plasma sample-taking easier. In order to do so, it was necessary to adapt pieces of cork by making holes inside them, where triatomines are placed without the possibility of escaping. This way, while lynxes sleep, this type of bugs bites felines and the blood from the insects’ abdomen is taken later.
With regard to the urine sample-taking, apart from the design of proper recipients, the treatment techniques have been improved in order to be able to detect the relaxine. In the urine, the level of this hormone is very low and it is necessary to apply an ultra filtration technique to the samples to detect it. The group of researchers has developed the whole suitable process so as to filter the urine but keeping the relaxine.
It is believed that relaxine relaxes the muscle of the abdomen during pregnancy, but at birth its level decreases as it is necessary for muscles to have the appropriate mobility to contract and retract. Therefore it is necessary to identify those pregnancy movements where the presence of relaxine is adequate for testing. It has been proven that the maximum concentration of this placental hormone in urine is between the 36 and 45 days of pregnancy, and it maximum presence in plasma us between the day 32 and 57 of the pregnancy.
’We have highly improved this pregnancy detection technique, but there is still a lot of work to do in the method to check the false negative results we rather often get’ , Vargas said; she stressed the need to find other techniques to ensure that the lack of relaxine is checkable.
