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Gene: 131	Name: Esrrg	Family: Nuclear Hormone Recept...	Subfamily: Orphan NHR	Accession: AF117254	GI: 5726227

Gene 131
Summary of Phenotypic Analysis

Changes related to genotype:

Perinatal Lethality: homozygous mutant mice do not survive to weaning age.
Behavior: Heterozygous mutant mice exhibited significantly increased overall startle amplitude when compared with age- and gender-matched wild-type control mice.

The genotypic ratio suggested a perinatal lethal phenotype.

Weaned progeny from the heterozygous matings were genotyped. Few homozygous mutant mice were identified by PCR, whereas wild-type and heterozygous mutant mice were present. The genotypic ratio suggested either a perinatal or juvenile lethal phenotype.

ES cells derived from the 129/OlaHsd mouse substrain were used to generate chimeric mice. F1 mice were generated by breeding with C57BL/6 females. F2 homozygous and heterozygous mutant mice were produced by intercrossing F1 heterozygous males and females.

Wild-type control mice, and heterozygous mutant and homozygous mutant mice were evaluated by the following examinations or tests:

Physical examination
Necropsy, including body length, body weight, and organ weight measurements
Histological examination of tissues and organs
Bone marrow section evaluation
Complete blood counts and differential cell counts
Clinical chemistry panels
Densitometry
Behavioral tests

Gene 131
Behavior

Heterozygous mutant mice exhibited significantly increased overall startle amplitude when compared with age- and gender-matched wild-type control mice.

Heterozygous mutant and wild-type control mice were evaluated for phenotypic changes by testing on seven behavioral tasks: Open field test, Tail suspension test, Rotarod test, Startle response/PPI test, Tail flick test, Hot plate test, and Metrazol test.

Mouse ID numbers are as follows for the N1 generation:
11 heterozygous mutant males (327905, 329529, 329691, 329692, 329693, 338789, 338791, 338793, 347648, 347649, 347651)
31 wild-type control males (255247, 255248, 317396, 321777, 321803, 322737, 323648, 324922, 327393, 327548, 327760, 327903, 329607, 330549, 330830, 336263, 337442, 338583, 338788, 339003, 341641, 341870, 341979, 342143, 342388, 343816, 345378, 345830, 345898, 347530, 349486)

ES cells derived from the 129/OlaHsd mouse substrain were used to generate chimeric mice. F1 mice were generated by breeding with C57BL/6 females. The resultant F1N0 heterozygotes were backcrossed to C57BL/6 mice to generate F1N1 heterozygotes. F2N1 heterozygous mutant mice were produced by intercrossing F1N1 heterozygous males and females.

Behavior Findings:
When compared to age- and gender-matched wild-type control mice, heterozygous mutant mice exhibited a significant increase in overall startle amplitude, indicating a possible hypersensitivity to sound-induced motor reflex in these mice.

There were no other genotype-related differences noted between heterozygous mutant and wild-type control mice for any other parameters evaluated during behavior testing.

Gene 131
Expression Summary

Taqman Summary:
The highest levels of RNA transcripts are detectable in salivary gland and stomach.

Moderate levels of RNA transcripts are detectable in: whole brain, cortex, subcortical region, cerebellum, brainstem, olfactory bulb, spinal cord, eye, Harderian glands, heart, kidney, lymph nodes, gallbladder, pituitary gland, adrenal gland, tongue, epididymis, coagulating gland, prostate gland and white fat.

Lower levels of RNA transcripts are also detectable in lung, liver, pancreas, spleen, thymus, bone marrow, skin, urinary bladder, skeletal muscle, small intestine, cecum, colon, testis, seminal vesicle, ovary and uterus.

LacZ Summary:
Striking lacZ expression was detected in the central nervous system, eyes, heart, kidney and cervix. Strong to very strong lacZ expression was detected throughout the wholemount brain as well as in sections of cerebrum, cerebellum, brainstem and spinal cord. In the eyes, very strong expression was detected in retina and ciliary body with moderate to strong expression in lens. Very strong staining was also observed throughout the myocardium. In kidney, very strong expression was detected throughout the cortex and medulla and in some cells of the papilla. The cervix shows very strong staining in the stratified squamous epithelium nearest the cervical canal.

LacZ expression was detected in: brain, spinal cord, eyes, thymus, lymph nodes, heart, lung, liver, pancreas, kidney, thyroid gland, pituitary gland, skeletal muscle, testis, prostate gland, cervix and adipose tissue.

LacZ expression was not detected in: sciatic nerve, spleen, bone marrow, aorta, urinary bladder, adrenal glands, skin, ovary and uterus.

Gene 131
Densitometry

There were no significant differences detected in the heterozygous mutant mice when compared with age- and gender-matched wild-type control mice.

The following mice were evaluated by dual-energy x-ray absorptiometry.

49 Day Cohort Mouse ID numbers are as follows:
3 heterozygous mutant females (282207, 282208, 282209)
4 heterozygous mutant males (282204, 284288, 284289, 284290)
2 wild-type control females (284294, 284295)
2 wild-type control males (282205, 282206)

Bone Mineral Density (BMD in g/cm² ), fat % (fat percentage expressed as a percentage of body soft tissue compartment), and R-value of soft tissue were calculated from Bone Mineral Content (BMC in g), bone and tissue areas (cm² ), and total tissue mass (g) generated by a PIXImus densitometer.

Densitometric Findings:

Incidental densitometric differences were present between some mice. These findings were considered to represent background differences occasionally seen in this strain of mice, differences due to spontaneous disease, age-related differences, and/or differences of a nonspecific etiology. They were not considered to be genotype related.

Gene 131
Histopathology

There were no significant differences detected in the homozygous or heterozygous mutant mice when compared with age- and gender-matched wild-type control mice.

Tissues from the following mice were evaluated histologically.

The following tissues were examined and considered to have no genotype-related abnormality: brain, pituitary gland, ears, nasal cavity, salivary glands, oral cavity, lymph nodes, aorta, lungs, liver, gallbladder, pancreas, spleen, kidneys, urinary bladder, stomach, small and large intestines, larynx, esophagus, trachea, thyroid gland, thymus gland, tongue, skeletal muscle, sciatic nerve, mammary glands, vertebrae, spinal cord, bone (skull, sternum, femur, tibia, and stifle joint), reproductive tract (including gonads), eyes, Harderian glands, integumentary system (skin and either clitoral or preputial glands), and bone marrow.

Bone marrow was examined in sections of sternum, vertebrae, and/or femur and tibia. Marrow cellularity, myeloid:erythroid (M:E) ratio, myeloid and erythroid maturation sequences, and numbers of megakaryocytes were evaluated.

Incidental lesions were present in some tissues. These findings are considered to represent background lesions occasionally seen in this strain of mice, lesions due to spontaneous disease, age-related lesions, and/or lesions of a nonspecific etiology. They were not considered to be genotype related.

Gene 131
Necropsy

There were no significant differences detected in the homozygous or heterozygous mutant mice when compared with age- and gender-matched wild-type control mice.

The following mice were necropsied. Body weight, body length, and organ weights were obtained, and gross pathological findings were recorded.

20 Day Cohort Mouse ID numbers are as follows:
1 homozygous mutant male (295341)

49 Day Cohort Mouse ID numbers are as follows:
3 heterozygous mutant females (282207, 282208, 282209)
4 heterozygous mutant males (282204, 284288, 284289, 284290)
2 wild-type control females (284294, 284295)
2 wild-type control males (282205, 282206)

Mice were examined for the following observables: adrenal glands, body length, body weight, bone marrow, bone - cranium, bone - femur, bone - sternum, bone - stifle joint, bone - vertebral column, brain, cecum, colon, duodenum, epididymis - seminal vesicle, esophagus, eyes, gallbladder, general appearance, Harderian glands, heart, heart weight, ileum, jejunum, kidney weight, kidneys, liver, liver weight, lungs, lymph nodes, mesentery, ovaries, pancreas, penis, salivary glands, sciatic nerve, scrotum, skeletal muscle, skin, skinned mouse, spleen, spleen weight, stomach, testes, testes - epididymis weight, thymus, thymus weight, tongue, trachea, urinary bladder, urine, uterus, and vagina. (Gender-specific observables apply to the appropriate gender.)

Necropsy Findings:

A 7 day homozygous mutant male (295341) was reported to have decreased subcutaneous fat. Since there is only a single homozygous mutant mouse to evaluate, and this mouse is at the young end of the 20 day historical population cohort, this finding is not being reported as a phenotypic change but is being presented for your consideration.

There were no genotype-related or biologically significant differences noted between mutant and wild-type control mice for any of the parameters evaluated at necropsy. Incidental lesions were present in some tissues. These findings were considered to represent background lesions occasionally seen in this strain of mice, lesions due to spontaneous disease, age-related lesions, and/or lesions of a nonspecific etiology. They were not considered to be related to genotype.

Body and Organ Weight Findings:

The body weight and organ weights for the 20 day cohort homozygous male (295341) were highlighted in the report as being low but there were no contemporaneous wild-type mice and too few wild-type mice near age 7 days in the database to establish appropriate historical control values. Additionally, there was only a single homozygous mutant mouse to evaluate. Therefore, these findings have not been reported as phenotypic changes but have been presented for your consideration.

Other differences in body length, body weight, organ weights, and/or organ weight to body weight ratios were present between individual mice. The variability between mice usually fell within our historical reference ranges and was not correlated with genotype.

Gene 131
Clinical Chemistry

There were no significant differences in the heterozygous mutant mice when compared with age- and gender-matched wild-type control mice.

Serum samples from the following mice were evaluated by a clinical chemistry panel. The data are compiled from the F2N0 and F2N1 generations.

49 Day Cohort Mouse ID numbers are as follows:
3 heterozygous mutant females (282208, 282210, 327893)
4 heterozygous mutant males (282204, 284289, 284290, 284291)
3 wild-type control females (284294, 284295, 284297)
2 wild-type control males (282205, 282206)

Values for the various analytes evaluated were generally similar between heterozygous mutant and wild-type control mice. Although variations in clinical chemistry values were present in some mice, they were not related to genotype and, thus, were not considered phenotypically relevant.

Gene 131
Hematology

There were no significant differences in the heterozygous mutant mice when compared with age- and gender-matched wild-type control mice.

Blood samples from the following mice were evaluated by a complete blood count and differential cell count. The data are compiled from the F2N0 and F2N1 generations.

49 Day Cohort Mouse ID numbers are as follows:
3 heterozygous mutant females (282208, 282210, 327893)
3 heterozygous mutant males (282204, 284289, 284291)
3 wild-type control females (284294, 284295, 284297)
3 wild-type control males (282205, 282206, 284292)

Although minor variations of hematological values were present in some mice, these changes were not related to genotype and, thus, were not considered phenotypically relevant.

Gene 131
Physical Examination

There were no significant differences detected in the homozygous or heterozygous mutant mice when compared with age- and gender-matched wild-type control mice.

The following mice were evaluated by physical examination.

7 Day Mouse ID number is as follows:
1 homozygous mutant male (295341)

49 Day Cohort Mouse ID numbers are as follows:
3 heterozygous mutant females (282207, 282208, 282209)
4 heterozygous mutant males (282204, 284288, 284289, 284290)
2 wild-type control females (284294, 284295)
2 wild-type control males (282205, 282206)

Mice were examined in detail as follows: anus, behavior, body shape, claws, coat - fur, coat color - back, coat color - belly, ear - left, ear - right, eye - left, eye - right, eye color - left, eye color - right, feces, forelimb - left, forelimb - right, forelimb number of amputated digits - left, forelimb number of amputated digits - right, forelimb number of digits - left, forelimb number of digits - right, general appearance, genitals - female, genitals - male, hair type, head shape, hindlimb - left, hindlimb - right, hindlimb number of amputated digits - left, hindlimb number of amputated digits - right, hindlimb number of digits - left, hindlimb number of digits - right, injuries, lesions, limb shape, locomotor, lumps - masses, mammary glands, mice in cage, respiration, skin appearance, snout, swelling - joints, tail, teeth color, teeth length, urine, and whiskers. (Gender-specific observables apply to the appropriate gender.)

A 7 day homozygous mutant male (295341) had flakey skin. Since there was only a single homozygous mutant mouse to evaluate and no histopathological correlate, this finding has not been presented as a phenotypic change but has been reported for your consideration.

Individual homozygous or heterozygous mutant mice had only other occasional minor differences in observed physical features compared to wild-type control mice. These findings were considered to represent individual variability, background features occasionally seen in this strain of mice, findings due to spontaneous disease, age-related findings, and/or findings of a nonspecific etiology. However, none of these differences was regarded as biologically significant or genotype related.