Project Life Ibriwolf - Result of genetic testing

We publish the technical report "Results of genetic testing" (Action A3 Project Life Ibriwolf), together with a summary. We can draw some general considerations relevant to the management of the problem of hybrids ...

The final report should be seen as an integral part of the "Technical Report of the actions A3 and A4" completed in July 2012. The results presented are a summary of the genetic analyzes performed by two different laboratories for analysis on a sample of 110 faeces and 25 specimens of biological remains of canids (Annex 1).

All excreta were collected in the territory of the Province of Grosseto in the period between January 2012 and April 2013. The reference period is more extensive than reported in the final report of the actions A3 and A4 as it is also considering the genetic analyzes carried out on samples collected after June 30, 2012, the date of completion of the actions A3 and A4.

With regard to biological samples, most of these derives from specimens found dead during the fact-finding investigation carried out under the actions A3 and A4 or found in the recent past ( 2010-2013 ) by other operators in the area of the Province of Grosseto and in areas adjacent to this. Some of these individuals sampled showed phenotypic characteristics can be attributed to a hybridization event, generally identifiable in a dark mantle and the absence of facial mask (eg copies corresponding to the samples CAPI 5, 16 HEADS , HEADS 164 HEADS 18, Images 1-4 ).

The details of the genetic analyzes carried out on samples invasive ( CI ), or biological remains , and non-invasive (NI), or droppings, are described in " Materials and Methods ".

Genetic analyzes carried out on a sample of 110 droppings (CNI ) and 25 biological remains (CI), corresponding to 135 total samples of specimens of canids found from 2010 to 2013 in the province of Grosseto and in areas immediately adjacent to this (the provinces of Siena and Florence areas bordering the province of Grosseto ) gave the following results:

 

  • We have identified a total of 57 genotypes which correspond to a number between 17 and 20 copies introgressed (ie "hybrid" ) and to a number between 29 and 32 wolves. The dogs identified are only 7 (12.3% of the sample).
  • The number of specimens introgressed increases if we takes into account the analysis performed at ISPRA that include exemplary HEADS 15 (Picture 6 ) .
  • If we exclude specimens dead or captured from the total of introgressed specimens (which are no longer part of the current population ), and if we limited to samples collected in the years 2012 and 2013 in the Province of Grosseto, the results of genetic tests made ​​by laboratories American and Portuguese and ISPRA shows that at least 11 hybrid specimens are currently present in the area of the Province of Grosseto.
  • The sex of the animals was determined for 37 individuals who are 16 females and 21 males.
  • Given that the samples were collected only in mountainous areas and forests, away from population centers, the number of dogs sampled is definitely not representative of the number of stray dogs actually present in the territory .
  • For both threshold values ​​considered ( qi and qi ≥ 0.95 > 0.975 ) 8 introgressed specimens showed genetic evidence of hybridization detected simultaneously in more than one genetic marker .
  • Four of the five animals for which it is known the morphological appearance and for which they have been observed phenotypic evidence attributable to an event of hybridization showing evidence of hybridization in at least one genetic marker among those analyzed.
  • In cases in which the individual introgressed derives from a backcross of the second or subsequent generation its identification of the genetic basis becomes problematic and genetic techniques currently used are quite limited in the possibility to go back to the original generation of hybridization. 

From the results of analyzes carried out is possible to make some general considerations that constitute a useful reference for the management of the problem of wolf - dog hybridization in the Province of Grosseto:

  1. There has been a high percentage of individuals, including those sampled in the Province of Grosseto, with at least one genetic evidence for introgression. Although this does not constitute unequivocal evidence of recent hybridization, confirming the initial doubts that led to the formulation of this project.
  2. In this context it should be noted that the degree of introgression detected in the sampled population is a rough estimate of the actual number of dog - wolf hybrid individuals in the population , as genetic analysis , however accurate they may be, often fail to identify individuals introgressed generated by successive generations to the second.
  3. Furthermore, the genetic markers currently used to determine the degree of introgression of the genome of the dog in the wolf population does not allow us to determine when this introgression has occurred, or are not able to determine with certainty the class of the specimen sampled, if this belongs to a generation of backcrossing after the second (F2).
  4. It is therefore a priority for the immediate future to identify an approach to diagnosis that is additional and complementary to the genetic analysis, whic has practical implications more applicable in a managerial context, starting from the premise that the ability to reliably identify individuals hybrids and introgressed into population is essential to correctly set a management strategy.
  5. This approach must provide, in addition to the utilization of more genetic markers, the integration of the genetic data with the phenotypic appearance so as to enhance the respective diagnostic powers for the detection of hybrid specimens .
  6. From the management point of view, and given the high proportion of hybrids / introgressed later than the second generation (F2) detected in the province, must be contemplated the possibility that hybrid specimens are considered as such regardless of the generation time can be determined only on the basis of genetic .

Authors of the Report: Chiara Braschi and Luigi Boitani, Department of Biology and Biotechnology "Charles Darwin ", University of Rome "La Sapienza" .

 
Download (pdf) Technical report the results of genetic investigations >>>

Download ( Excell ) : Annex 1 , Annex 2 , Annex 3 , Annex 4

Look at all the other technical reports >>>

 

 

 
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