**6. A reality**

The patrimonial cryobank for rabbit species is henceforth a reality. It allows to satisfy the expectations of breeders, selectors and the actors of research and biomedical industries. This last actor takes a more and more important rules in the rabbit production.

A standard method of rabbit embryos cryopreservation has been routinely applied for 15 years. Its implementation is performed on the field with a portative controlled rate freezer. This method requires a simple stimulation of the females before the collection, and an appropriate choice of the males for the breeding combinations. However, the complete conditions are not always encountered and this method is not efficient in emergency situation (for example, when an animal is rugged or during sanitary crisis).

So, another complementary methods are studied. These new way of research includes the cryopreservation of testicular tissue and epididymal spermatozoa in the male which are dead for less than two days. It includes also the cryopreservation of the rabbit ovarian tissue. Nowadays, the freezing of ear's fibroblasts is studying to produce Induced Pluripotent Stem Cells in order to use it for chimaeric animal production as tool of regeneration of initial population without genetic drift.

#### **7. References**

184 Current Frontiers in Cryopreservation

while uncontrolled conditions are defined by a recipient placed in an uncontrolled environment (sanitary, light, temperature) in a traditional farm's breeding conditions.

Globally, 76% of the recipients give birth to young rabbits after thawed embryo transfer with an embryo development rate of 36%. It is particularly important to control the recipient's genotype and the breeding conditions in order to guarantee the population

The efficiency of the cryoconservation method has been concretely proved after transfer of embryos stored for more than 15 years in liquid nitrogen. In November 2006, 69 Brun Marron de Lorraine young rabbits got born after thawing and transfer of 134 embryos in recipients. The young rabbits born from frozen embryos of 1992 were presented to public at the international agriculture show in Paris in March 2007, in collaboration with fancy

In March 2008, the rabbit collections presented a large genetic diversity, which could be ranged according to three types of materials previously defined. Nearly sixty of rabbit populations have been cryopreserved. More than 19.000 embryos from about 1.300 rabbit doe donor have been frozen and are currently stored in liquid nitrogen at -196°C. For all these populations, three methods of embryos production have been applied according to the situation and the physiological state of rabbit does (superovulation, eCG, simple induction of ovulation). Then, all these embryos were treated according to the same freezing protocol (Joly *et al*, 1998). All the actors working for the rabbit populations management are henceforth convinced of the interest of this tool. They have actively participated to the building of the rabbit French cryobank. Public and private selectors, associations of fancy

The patrimonial cryobank for rabbit species is henceforth a reality. It allows to satisfy the expectations of breeders, selectors and the actors of research and biomedical industries. This

A standard method of rabbit embryos cryopreservation has been routinely applied for 15 years. Its implementation is performed on the field with a portative controlled rate freezer. This method requires a simple stimulation of the females before the collection, and an appropriate choice of the males for the breeding combinations. However, the complete conditions are not always encountered and this method is not efficient in emergency

So, another complementary methods are studied. These new way of research includes the cryopreservation of testicular tissue and epididymal spermatozoa in the male which are dead for less than two days. It includes also the cryopreservation of the rabbit ovarian tissue. Nowadays, the freezing of ear's fibroblasts is studying to produce Induced Pluripotent Stem Cells in order to use it for chimaeric animal production as tool of

**5. The national cryobank: A saving tool of rabbit genetic resources** 

breeders and different groups of independent breeders are regular depositor.

last actor takes a more and more important rules in the rabbit production.

situation (for example, when an animal is rugged or during sanitary crisis).

regeneration of initial population without genetic drift.

recreation after cryoconservation.

**6. A reality** 

breeders and the FFC (Salvetti *et al.,* 2007).


**10**

*Sweden* 

*University of Gothenburg* 

**(days)** 

21

ovulatory 16-17 (Seasonal)

**Review on Ovarian Cryopreservation in Large** 

The ultimate aim of ovarian cryopreservation research is naturally to increase the effectiveness of this fertility preservation procedure in female cancer victims and much of this research on whole ovary cryopreservation, ovarian cortex cryopreservation and transplantation has been performed in animal models. However, ovarian cryopreservation could also be used in the future in programs with the purpose to rescue endangered species (Santos et al., 2010) and certain specific strains of animals (Dorsch et al., 2004). Due to the ethical barriers in the research on human tissue and the shortage of human premenopausal ovarian tissue for research purposes, there is a need to find animal models that are reasonably analogous to the human. As a general rule, animal models have to be comparable in biochemical, physiological and anatomical characteristics to the human so that the results can be applicable to human conditions (VandeBerg, 2004). Regarding research of ovarian cryopreservation for human fertility preservation, a similar tissue architecture and size of the ovary (Table 1) as well as being a mono-ovulatory species with the primordial follicles located superficially in the cortex would be of advantage (Gerritse et al., 2008). The previous research on ovarian cryopreservation using bovine, porcine, sheep

**Species Ovarian volume Tissue architecture Ovulation pattern Cycle length** 

Similar to the human

Less fibrous than

Similar to the human

Similar to the

Mono, diovulatory

Mono, tri-

human Mono-ovulatory 28-32

the human ovary Multi ovulatory 18-24

and non-human primate models will be presented in this chapter.

**Cow** 14.3 (+/- 5.7) cm3

**Pig** 7.3 (+/- 2.2) cm3

**Sheep** 1.0 (+/- 0.4) cm3

**Non-human primate (cynomolgus macaque)** 

(Gerritse et al. 2008)

(Gerritse et al. 2008)

(Gerritse et al. 2008)

0.258 (+/- 0.159) cm3 (Jones, 2011)

Table 1. Ovarian characteristics of different large animal models

**1. Introduction** 

**Animals and Non-Human Primates**

Milan Milenkovic, Cesar Díaz-Garcia and Mats Brännström *Department of Obstetrics and Gynecology, Sahlgrenska Academy* 

