Genetic Rescue at a Glance
Genetic Rescue at a Glance
� Crossbreeding increases genetic diversity and preserves at-risk populations from extinction . � Starting crossbreeding early can prevent a dramatic decline in genetic variation and the risk of health problems . It also improves the chances of success and limits the amount of genetic input needed from other populations . � With careful selection and time , it is possible to maintain certain breed traits . � The need for genetic rescue can be greatly reduced if breeders understand and use modern science to evaluate the consequences of transmitting genes that may bring disease , reduced quality of life and potentially lowered life expectancy .
Left : The Lundehund is a dog breed with deep connections to the Norwegian coastal landscape . Photo by Arild Espelien .
PHOTOS COURTESY INGVILD SVORKMO ESPELIEN
2 . If distinct physical characteristics of a breed may cause health problems , should these traits be discouraged in breed planning ?
So , how long should we wait before initiating genetic rescue ? As long as possible , in an attempt to avoid outcrossing and the risk of permanently changing the breed / population ? Or do we prefer an early start to avoid the chance of illness and inbreeding ? Is it possible to develop some general guidelines to handle this difficult balance ?
The program started relatively late for the Lundehund , which by then showed obvious health problems and comprised only highly related individuals . The breed has a high prevalence of IL , and fecundity is low , as litters with only one pup are common , a feature associated with inbreeding depression in species with high litter size . The program is nevertheless expected to bring clear benefits for Lundehund genetic diversity and health .
There will hopefully also be opportunities to compare progress for the Lundehund with that of other populations in which rescue was started earlier . In such cases , genetic diversity and survival may be increased by outcrossing with only a few individuals , which would probably simplify the process of selecting and maintaining desired anatomical and behavioral traits .
This brings us to breed traits that may cause health problems . Following strong artificial selection , many breeds have developed distinct physical characteristics that may cause pain in the back or hips , skin problems , difficulties with breathing , reduced lifespan and other health issues . If such traits have negative consequences for health , wellbeing and life expectancy , should they be discouraged in breed planning ?
The crossbred Lundehund pups will likely contribute to our understanding of whether particular genes cause gastrointestinal disease and whether polydactyly carries inherent negative consequences . The knowledge gained from the outcrossing project might eventually change breeding standards for the Lundehund and those of other breeds . Without changes in breeding standards , problems may otherwise reappear by selection for individuals with unhealthy anatomy and physical condition . For the Lundehund , the focus on well-developed extra toes may initially need to be reduced , particularly if any connections should be found between IL and polydactyly .
Additional information about the outcrossing project and updates about crossbred litters can be found at the Norwegian Lundehund Club website ( in Norwegian ), www . lundehund . no . DIR
Monrad Mikalsen and Tutta : The last known location where the Lundehund was used for hunting by traditional methods was the fishing village of Måstad in the Lofoten Islands . This historical photo from Måstad shows Monrad Mikalsen relaxing with his dog Tutta . Monrad Mikalsen played a key role in the efforts to save the Lundehund from extinction in the early 1960s .
About the author :
Dr . Carol Beuchat is a vertebrate biologist with more than 30 years of experience in the field and the laboratory . She founded the Institute of Canine Biology to bring scientists studying various aspects of canine biology together with dog breeders and owners . Carol sits on the Board of the Mongolian Bankhar Dog Project , and she is a member of the Species Survival Commission of the Conservation Breeding Specialist Group at the International Union for Conservation of Nature . She has an English Springer Spaniel from Finland named Finn .
MARCH 2017 DOGS IN REVIEW 99