**2. Genetic diversity in rabbit species**

The archaeological origins of rabbit are located in Spain (Bolet et al., 2000). Actually, rabbit is widely spread all around the world and can be considered according situations as wild animal, domestic animal, pets and laboratory models. The rabbit populations can be classified into 3 categories according to their genetic originality, their specific uses and the motivations of breeders involved in the *in situ* management of populations (figure 1).

#### **2.1 "Type I" material**

Type I regroups the breeds identified according to an official standard, as well as for large breeds (Butterfly, Champagne Argente, Fauve de Bourgogne...) and endangered breeds with less than 100 females (Brun Marron de Lorraine ...). These breeds are reared by fancy breeders and animals are presented regularly in local or regional meetings supported by FFC the federation of French fancy rabbit breeders (www.ffc.asso.fr). These breeds must be preserved for their patrimonial values and socio cultural interests.

Based on the conservation of germinal cells, this way helps to conserve the gene pool of

Mature spermatozoids (sperm collected in artificial vaginas) or immature (epididymal spermatozoids, spermatogonies in gonadic tissue) helps to save the male line. The freezing of an individual's semen (n generation) helps to obtain progeny (n+1 generation) after

Semen samples of bad quality can be promoted by new technologies of *in vitro* fertilization (FIV) or intracytoplasmic sperm injection (ICSI), which then permits *in vitro* embryo production and progeny delivering after embryo transfer in synchronized recipient female (Daniel *et al*, 2007). Nowadays, semen freezing is not a reliable or repeatable method yet, and results after AI with rabbit frozen semen are still too inconstant to plan a routine utilization of this technique (Vicente *et al*, 1996; Moce *et al*, 2003). Only half of the sampled males can produce semen with freezable quality and approximately 50% of females give birth after insemination of thawed semen with a large variability [15%~80%]. However, this is the only available method to preserve precious males semen, mainly for type I and II.

Mature oocytes (picked up in oviduct 15 hours after ovulation) or immature oocytes (present in follicles of ovarian tissue) permits to save genetic resources by female way and to preserve cytoplasmic heredity. Mature oocytes freezing of a female individu (n generation) would permit to obtain progenies (n+1 generation) after FIV or ICSI, but no young rabbit has been obtained from thawed oocytes yet (Salvetti *et al*, 2010). But, recently, young rabbits obtained from frozen ovarian tissue are born from females transplanted by orthotopic autograft (Almodin *et al*., 2004; Neto *et al*., 2007). In emergency situations (sanitary problems, injured animals), ovarian cortex freezing, even if this method is not yet completely under control (Neto *et al.,* 2008), can be proposed to save the heredity pool of an important female of type II.

Fig. 2. Biotechnologies of reproduction applied to the cryopreservation of the rabbit genetic

**3.1 Germinal cells** 

resources

particular male or female individuals.

thawing and artificial insemination (AI) of females.
