3Some important “normal” mouse breeding characteristics Sexual maturity at roughly 5-8 weeks of ageEstrus cycle: 4-5 days19-21 day gestation periodAverage litter size: 6-8 pupsPups must be weaned at 3-4 weeks of age to prevent unplanned matingsCoat color can be distinguished starting at about8-9 days of age
4Some important “normal” mouse breeding characteristics Female fertility starts to decline at about6-8 months of age, while males usually remain fertile for at least a yearFemales can become pregnant within a day of giving birth (postpartum estrus)Multiple females can be mated with a single male, but not vice versaMales used for breeding must not be housed with other males
5配種方式(1)持續交配：雌鼠被允許永久與雄鼠及群體其他成員相 處並產下仔鼠。 此系統乃利用產後發情方式繁殖。 a .一夫一妻：一隻公鼠一隻母鼠關在一起。 b .一夫多妻：一隻公鼠及多隻母鼠關在一起。 (2)暫留交配；在分娩之前將公鼠和母鼠暫時分開。 a . harem系統，公鼠及母鼠關在一起至分娩前才分開。 b. 人工控制交配系統；公鼠和母鼠關在一起一段充分的時間進行交配(通常約1個星期)。
6PHEROMONE EFFECTSLee-Boot Effect Housing female mice in groups will result in synchronization of their estrus cycles. Prolonged absence of male pheromones results in a state of anestrus (lack of a normal estrus cycle).Whitten Effect Estrus can be induced in most group-housed females by adding male mouse urine (or dirty bedding from a male’s cage) to their cage.Bruce Effect Pheromones from a strange male can prevent the implantation of embryos into the uterine walls of a recently bred female. This is why one should not move a female from one male’s cage to another.
7Replacement of breeders Replace a breeder pair if:they have not produced a litter in more than two months,they are producing small litters (1-3 pups per litter),they are killing their pups.
14Sizing Mouse ColoniesTo properly size a research mouse colony, many factors must be considered, including the following:• Number of mice needed, utility of each sex, needs for specific genotypes and age-matched mice• Number of strains needed (for example, a cre-lox experiment may require three breeding colonies)• Preferred breeding scheme• Strain productivity, genotypes and phenotypes affecting productivity, and number of unproductive matings• Female’s reproductive life span, average number and frequency of litters• Average number of pups per litter, average sex ratio per litter, and percent survival to weaning and adulthood• Breeder replacement schedules• Cage requirements, mouse room space, pair or trio breeding schemes, and allowable mouse density per cage (ACUC regulations)
17AN EXAMPLE OF LOW-LEVEL MAINTENANCE Mat.cage 1cage 2Holding cage7 pups5 pups4 males5 females3 males3 wks old2 wks old15 wks old10 wks old8 wks oldThe progeny from mating cage 1 are ready to be weaned. Three females and four males are found. They are numbered and placed in two cages. The two cages of older progeny are discarded (shaded boxes). Result: no change in cage number.
18Mat.cage 1cage 2Holding cage8 pups5 pups3 males4 males3 femalesnewborn3 wks old11 wks old9 wks old4 wks oldThe progeny from mating cage 2 are ready to be weaned. Two females and three males are found and numbered. The females are added to the cage of 3 females created in week 1, while the males are put into a new cage. The oldest cage of male progeny is discarded (shaded). Result: no change in cage number.
19Mat.cage 1cage 2Holding cage8 pupsNo pups4 males5 females3 males1 wk old9 wks old5 wks old4&5 wks old4 wks oldThe oldest male progeny can be discarded (shaded). No other action is necessary. Result: cage number reduced to five.
25Nomenclature of Inbred Strains 具簡潔獨特性之符號，以英文大寫字母或字母連結數字表示based on coat colorDBA (Dilute Brown nonAgouti,first inbred mouse)based on originNZW (New Zealand White)based on phenotypeNOD (Non-Obese Diabetic)othersBALB/c, C57BL, 129
26Standard Abbreviations Strain129P129P3/JLC57L/J129S129S1/SvImJCBACaCBA/CaGnLeAHeA/HeJCBCBAAA/JC3C3H/HeJAKAKR/JC3FeC3HeB/FeJCByBALB/cByJD1DBA/1JCBALB/cJD2DBA/2JBC57BLNZBNZB/BlNJB6C57BL/6JNZWNZW/LacJB10C57BL/10JSJL or JSJL/JBRC57BR/cdJSWSWR/J
28Nomenclature of Inbred Substrains [原始品系] / [序號(可省略)][實驗室編碼(Lab Code)]
29A Laboratory Code Narl ：National Applied Research Laboratories The Institute for Laboratory Animal Research (ILAR) maintains the International Laboratory Code Registry (Lab Codes).The purpose of this database is to accurately identify at which laboratory or institution a strain of animals was bred and maintained.Environmental factors can affect the characteristics of a strain, it is important to document where a strain originatedJ：The Jackson LaboratoryN：National Institutes of HealthCrl：Charles River LaboratoriesRik：The Institute of Physical and Chemical Research (RIKEN)Narl ：National Applied Research Laboratories (國家實驗研究院 國家實驗動物中心)C57BL/6JNarl
34Nomenclature of Congenic Inbred Strains [Recipient Strain*].[Donor Strain*] ▬ [基因]*英文大寫縮寫所導入之基因及其對偶基因來自於donor strainB6.AKR-H2krecipient strain：C57BL/6Jdonor strain：AKRB6.129P2-Tcrbtm1Momrecipient strain ：C57BL/6Jdonor strain ：129P2 via E14TG2a ES cell line若donor strain 不是inbred，而是雜交、遺傳背景混雜或未知時，以“ Cg ”表示之B6.Cg-Tcrbtm1Mom
35Nomenclature of Congenic Inbred Strains R1 ES cell (129X1/SvJ x 129S1/Sv)B6.Cg-Apoa1tm1Unc/J
36Nomenclature for Targeted Mutations 品系(/旁系)▬基因 tm[serial number][Lab Code]以 tm 代表 targeted mutationSerial number :來自於實驗室原始編號Lab Code :突變株所來自之實驗室129X1-Cftrtm1Uncthe first targeted mutation of the cystic fibrosis transmembrane regulator (Cftr) gene at 129X1, produced at the University of North Carolinaknock-out129X1-En1tm1(Otx2)Wrstthe coding region of En1 was replaced by the Otx2 gene, originating from the W. Wurst laboratoryknock-inB6.Cg-Apoa1tm1Unc/J
37小鼠編號方式Figure 1.1. A small metal ear punch can be used to mark the ears of mice at specific locations to create a numerical code for individual mouse identification.
38Figure 1.2. Dorsal view of a mouse showing commonly used numerical code approach for ear notching.
39Figure 1. 3. Ventral view of a mouse to orient feet Figure 1.3. Ventral view of a mouse to orient feet. Digits can be amputated on neonatal mice as a form of numbering individuals.
40Figure 1.4. Tattoo ink can be injected into the skin at specific locations, as indicated, in neonatal mouse feet to create a numerical code to identify individuals.