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Gene: 401	Name: G401	Family: Channel	Subfamily: Chloride	Accession: AK035512	GI: 26330711

Gene 401
Summary of Phenotypic Analysis

Changes related to genotype:

Necropsy:

Liver, enlarged, homozygous male
Liver, increased weight, and increased liver weight to body weight ratio, homozygous females and males

Histopathology:

Liver, hepatocytes, hypertrophy, homozygous female and homozygous males
Liver, hepatocytes, necrosis, multifocal, homozygous male

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 mutant mice were produced by intercrossing F1 heterozygous males and females.

Wild-type control mice 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

When compared to age- and gender-matched wild-type control mice, genotype-related differences involving the liver were present in homozygous mice. At necropsy, one homozygous male had an enlarged liver, and liver weights and liver weight to body weight ratios were increased in two of three homozygous females, and in all homozygous males. Histologically, one homozygous female and all homozygous males had hepatocytic hypertrophy which was characterized by increased amount of granular eosinophilic cytoplasm. The lesion was predominantly centrilobular in the female and in one male. One homozygous male also had multifocal hepatocytic necrosis.

Gene 401
Expression Summary

Taqman Summary:
The highest levels of RNA transcripts are detectable in skin, urinary bladder, tongue and uterus.

Moderate levels of RNA transcripts are detectable in: eye, pancreas, thymus, gallbladder, stomach, epididymis, seminal vesicle, prostate gland, ovary and white fat.

Lower levels of RNA transcripts are also detectable in: olfactory bulb, Harderian glands, heart, lung, kidney, spleen, lymph nodes, adrenal gland, salivary gland, skeletal muscle, small intestine, large intestine, cecum, testis and coagulating gland.

No RNA transcripts are detectable in: whole brain, cortex, subcortical region, cerebellum, brainstem, spinal cord, liver, bone marrow and pituitary gland.

LacZ Summary:
LacZ expression was detected in some of the organs examined. Expression was detected in epithelium in the urinary bladder, trachea and skin and in tracheal cartilage. Staining was observed in a few spermatogenic cells in the testis and stromal cells in the ovary. A small piece of tissue adjacent to the heart also showed staining.

LacZ expression was detected in: heart, urinary bladder, trachea, skin, testis and ovary.

LacZ expression was not detected in: brain, spinal cord, sciatic nerve, eyes, thymus, spleen, lymph nodes, bone marrow, aorta, lung, liver, pancreas, kidney, urinary bladder, thyroid gland, parathyroid gland, pituitary gland, adrenal glands, skeletal muscle, prostate gland, uterus and cervix.

Gene 401
Densitometry

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 dual-energy x-ray absorptiometry.

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 401
Histopathology

Changes related to genotype:

Liver, hepatocytes, hypertrophy, homozygous female and homozygous males.
Liver, hepatocytes, necrosis, multifocal, homozygous male.

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

Tissues from the following mice were evaluated histologically.

When compared to age- and gender-matched wild-type control mice, hepatocytic hypertrophy was present in the liver of one homozygous female (393000) and all homozygous males. This lesion was predominantly centrilobular in the homozygous female and in one homozygous male (393004). It was characterized by an increased amount of granular eosinophilic cytoplasm. Multifocal hepatocytic necrosis was also present in one homozygous male (393004). These lesions correlated with increased liver weight and liver weight to body weight ratio in these same mice, and also with gross liver enlargement in one homozygous male (393004).

No Significant Abnormalities:

The following tissues were examined and considered to have no genotype-related abnormality except as specifically noted above: brain, pituitary gland, ears, nasal cavity, salivary glands, oral cavity, lymph nodes, aorta, lungs, gallbladder, pancreas, spleen, kidneys, adrenal glands, urinary bladder, stomach, small and large intestines, larynx, esophagus, trachea, thyroid gland, thymus, 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 also 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 genotype related.

Gene 401
Necropsy

Changes related to genotype:

Liver, enlarged, homozygous male.
Liver, increased weight, and increased liver weight to body weight ratio, homozygous females and males.

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

49 Day Cohort Mouse ID numbers are as follows:
3 homozygous mutant females (393000, 393001, 393043)
3 homozygous mutant males (393004, 393006, 395129)
3 heterozygous mutant females (404074, 404075, 404076)
2 heterozygous mutant males (404068, 404071)
1 wild-type control female (393045)
2 wild-type control males (393002, 437835)

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:

When compared to age- and gender-matched wild-type control mice, one homozygous male (393004) had an enlarged liver. This correlated with increased liver weight and liver weight to body weight ratio in this homozygous male (see below).

There were no other 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:

When compared to age- and gender-matched wild-type control mice, two of three homozygous females (393000, 393043) and all homozygous males had increased liver weight and liver weight to body weight ratios, but the increases were small for one of the homozygous females (393043). The weight and ratio increases correlated with gross liver enlargement noted in one homozygous male (393004), and also with histopathological hepatocytic hypertrophy in one homozygous female (393000) and in all homozygous males.

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 401
Clinical Chemistry

There were no significant differences in the homozygous or 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 N0F2 and N1F2 generations.

49 Day Cohort Mouse ID numbers are as follows:
4 homozygous mutant females (393000, 393001, 393043, 395139)
4 homozygous mutant males (393004, 393006, 395129, 395130)
4 heterozygous mutant females (404074, 404075, 404076, 404077)
3 heterozygous mutant males (404059, 404071, 437836)
1 wild-type control female (393045)
1 wild-type control male (393002)

When compared to age- and gender-matched wild-type control mice, one of four homozygous mutant males (395129) and one of four homozygous mutant females (395139) had increased levels of cholesterol and high density lipoprotein. We are not reporting these findings as phenotypic changes, but we present them here for your consideration.

Values for the other various analytes evaluated were generally similar between 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 401
Hematology

There were no significant differences in the homozygous 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 N0F2 and N1F2 generations.

49 Day Cohort Mouse ID numbers are as follows:
3 homozygous mutant females (393000, 393001, 393043)
4 homozygous mutant males (393004, 393006, 395129, 395131)
3 heterozygous mutant females (404074, 404075, 404078)
2 heterozygous mutant males (404060, 437836)
1 wild-type control female (393045)
2 wild-type control males (393002, 437835)

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 401
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.

49 Day Cohort Mouse ID numbers are as follows:
3 homozygous mutant females (393000, 393001, 393043)
3 homozygous mutant males (393004, 393006, 395129)
3 heterozygous mutant females (404074, 404075, 404076)
2 heterozygous mutant males (404068, 404071)
1 wild-type control female (393045)
2 wild-type control males (393002, 437835)

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.)

Individual mutant mice had only 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 were regarded as biologically significant or genotype related.