Mouse strains and sexual divergence in corneal innervation and nerve regeneration.

A variety of mouse strains and sexes are used in studies of corneal wound healing and nerve regeneration. However, there is a gap of knowledge about corneal nerve density and its function in different mouse strains and sexes. In this study, we report a strain divergence of total and substance P (SP) sensory corneal nerves in uninjured mice. The BALB/c mouse showed the highest nerve density, corneal sensitivity, and tear volume followed by CFW and then C57BL/6. No differences were found in total nerves and SP-positive nerves between sexes. After injury damaged the corneal nerves, an important role for mouse strains, biologic sex, and their association to corneal nerve regeneration was identified. All female mice have a faster nerve regeneration rate than males. The molecular mechanism of this sexual divergence involves higher secretion neurotrophic factors in tears, which in turn modulate gene expression in trigeminal ganglion neurons. An important upstream signaling regulator was ß-estradiol, and topical treatment with ß-estradiol confirmed its function in corneal nerve regeneration. In conclusion, our study shows that the strain and sex of laboratory mice significantly affect the different indicators of corneal innervation and nerve regeneration. Researchers investigating corneal diseases should carefully consider these factors.-Pham, T. L., Kakazu, A., He, J., Bazan, H. E. P. Mouse strains and sexual divergence in corneal innervation and nerve regeneration.

Incidence of Mucinous Metaplasia in the Prostate of FVB/N Mice (Mus musculus).

Prostate epithelium in mice is considered to be relatively resistant to aged-related changes, as compared with human prostate epithelium, which is prone to spontaneous hyperplasia and cancer, for example. In addition, the incidence of metaplasia in mouse prostate typically is considered to be low. Here we report the incidence of mucinous metaplasia in the prostates of wild-type FVB/N mice. Our histologic study shows that mucinous metaplasia involving goblet cells occurs much more frequently (incidence as high as 50%) in the prostates of aged mice (17-24 mo) than has been reported previously. Mucinous metaplasia in the prostates of laboratory mice may be considerably more frequent than previously appreciated.

Unusual anatomical origins of the coronary arteries in C57BL/6 mice. Are they strain-specific?

A previous manuscript [Fernández B, et al. (2008) J Anat 212, 12] reported on the unusual coronary artery patterns in mice belonging to the C57BL/6 strain. The aim here was to elucidate whether this pattern is unique to C57BL/6 mice or appears in other laboratory mouse strains and in wild-living mice. Stereomicroscopy, scanning electron microscopy, light microscopy and a corrosion cast technique were used to examine 597 adult mice belonging to three inbred strains (C57BL/6, Balb/c, DBA/2), three outbred stocks (CD1, OF1, NMRI) two hybrid lines (129sv × BL/6, CD2F1) and wild mice. It was shown that lock-like ostium is an exclusive trait of C57BL/6 mice, whereas left septal artery, accessory ostium, high take-off, intramural course and solitary ostium in aorta are all present in the different laboratory strains and wild mice included in the present study. However, each mouse population shows a specific incidence of these coronary conditions. Several clinically relevant human coronary artery anomalies are present in healthy mice from different strains that may serve as animal models for humans. These results should be taken into consideration in research concerning the murine coronary system, especially in coronary artery occlusion experiments and in studies on cardiovascular developmental biology using murine mutant lines.

Accessing Data Resources in the Mouse Phenome Database for Genetic Analysis of Murine Life Span and Health Span.

Understanding the source of genetic variation in aging and using this variation to define the molecular mechanisms of healthy aging require deep and broad quantification of a host of physiological, morphological, and behavioral endpoints. The murine model is a powerful system in which to understand the relations across age-related phenotypes and to identify research models with variation in life span and health span. The Jackson Laboratory Nathan Shock Center of Excellence in the Basic Biology of Aging has performed broad characterization of aging in genetically diverse laboratory mice and has placed these data, along with data from several other major aging initiatives, into the interactive Mouse Phenome Database. The data may be accessed and analyzed by researchers interested in finding mouse models for specific aging processes, age-related health and disease states, and for genetic analysis of aging variation and trait covariation. We expect that by placing these data in the hands of the aging community that there will be (a) accelerated genetic analyses of aging processes, (b) discovery of genetic loci regulating life span, (c) identification of compelling correlations between life span and susceptibility for age-related disorders, and (d) discovery of concordant genomic loci influencing life span and aging phenotypes between mouse and humans.

Inbred wild type mouse strains have distinct spontaneous morphological phenotypes.

The mouse is the most commonly used animal for modelling human disease. New approaches for generating genetically manipulated mouse models to represent human disease, as well as target the function of specific genes, has increased the importance of mice in biomedical science. For the correct interpretation of alterations in mouse phenotype the basic morphology of background mouse strains must be known. Despite on-going efforts to create publicly available baseline phenotypic data, the information concerning spontaneous lesions in wild-type mice is incomplete and scattered so far, and further studies are needed. We addressed this problem by screening haematoxylin-eosin stained sections of brain, reproductive organs, urinary bladder, kidney, thyroid, parathyroid, heart, lung, spleen, thymus, lymph nodes, adrenal glands, stomach, intestine, liver, skin and pancreas of six commonly used inbred mouse strains (C57BL6/J, C57BL6/NTac, C3HeB/FeJ, BALB/cByJ, 129P2/OlaHsd and FVB/N) for inherent spontaneous morphological lesions. Interesting spontaneous phenotypes were seen in morphology of the liver, pancreas, adrenal glands, lungs, intestines and heart. In conclusion, care should be taken when choosing the background mouse strain for genetic manipulations, since different mouse strains harbour different inherent lesions that can affect the function of targeted genes, interpretation of results and translation of results to model human disease.

Morphological aspects of spermatogenic cells at different stages of sexual maturation in black isogenic C57BL/6/Uni Mice / Aspectos morfológicos de las células de la espermatogénesis en diferentesetapas de maduración sexual del ratón negro C57BL/6/Uni

In order to study the morphological changes that occur in cells of the testes of isogenic black mouse C57BL/6/Uni into three periods during spermatogenetic used 15 mice divided into 3 groups of 5 animals with 40, 50 and 60 days of age. The mice were sacrificed and weighed. Then weighed and measured the testicles, to be processed finalmete histologically and stained with HE, PAS and Masson Massom-H and evaluated under light microscopy. Was observed in group I with 40 days of age in the seminiferous tubules had a lumen with sparse small amount of interstitial tubular cells. In the seminiferous epithelium were identified type A spermatogonia, intermediate and B, which occupied the compartment adbasal and intermingled with these cells was observed in spermatocytes I in Pachytene and leptotene, whereas in the adluminal compartment Golgi phase spermatids observed in the presence of acrosomal granule. In group II, the cells of the seminiferous epithelium were developed and it was observed in round spermatids cephalic hood phase plus many elongated spermatids in acrosome phase and Sertoli cells. In Group III, 60 days old, it was found that the seminiferous epithelium which was of the tubules had elongated spermatids in acrosome phase and maturation, with elongated nuclei and acrosomal system typical of spermiation in the presence of sperm and residual bodies near the tubular lumen. So you can check the morphological evolution of germ cell testicular spermatids and recognize its four phases: Golgi, cap, acrosome and maturation over the age of the animal.

Con el fin de estudiar los cambios morfológicos que ocurren en las células del testículo del ratón negro isogénico C57BL/6/Uni en tres períodos diferentes del proceso espermatogenético; fueron utilizados 15 ratones divididos en 3 grupos (n=5) con 40, 50 y 60 días de edad respectivamente. Todos los animales fueron sacrificados y pesados. Posteriormente sus testículos se pesaron, midieron y procesaron histológicamente para HE, PAS y tricrómico Massom-H. Las muestras obtenidas fueron evaluados con microscopía de luz. En el grupo I con 40 días se observaron túbulos seminíferos con un lúmen pequeño y escaza cantidad de células intersticiales. En el epitelio seminífero se identificaron espermatogonias tipo A, intermedio y B, quienes ocuparon el compartimiento basal entremezclándose con espermatocitos I en paquiteno y leptoteno. En el compartimiento adluminal se observaron espermatidas de fase Golgi y presencia de gránulos acrosomales. En el grupo II de 50 días, se observaron células del epitelio seminífero desarrolladas, espermatidas en fase de capuz cefálico, muchas espermatidas elongadas en fase acrosomica y células sustentaculares. En el Grupo III de 60 días se observó el epitelio del túbulo seminífero con espermátidas alargadas en fase acrosómica y de maduración, con núcleos alargados y un sistema acrosomal típico de la espermiación, con presencia de espermatozoides y cuerpos residuales cerca del lúmen tubular. En conclusión se observa la evolución morfológica de las células germinativas testiculares y se reconocen las espermatides en sus cuatro fases: Golgi, capuchón, acrosomal y de maduración en las diferentes edades del animal.

Anatomic modifications in the enteric nervous system of JF1 mice with the classic piebald mutation.

The Japanese Fancy Mouse 1 (JF1) has a characteristic coat color similar to a very old mutant, piebald. The mutation in JF1 and the classic piebald was previously thought to be the same recessive allele in the endothelin B receptor gene (Ednrb) according to the haplotype pattern, which is insufficient for this conclusion. In this study, we identified the same insertion of a retroposon-like element in intron 1 of the Ednrb gene in JF1 as in the classic piebald mutation by PCR. Further, we investigated whether the intestine shows neuronal intestinal malformations such as hypoganglionosis and immaturity of ganglion cells by histochemical staining. Though it has been assumed that the defect of neural crest-derived lineages is restricted to melanocytes in JF1, we found that the enteric innervation and neuronal density were impaired throughout the whole colon in JF1 mice.

Epigenetic integration of the developing brain and face.

The integration of the brain and face and to what extent this relationship constrains or enables evolutionary change in the craniofacial complex is an issue of long-standing interest in vertebrate evolution. To investigate brain-face integration, we studied the covariation between the forebrain and midface at gestational days 10-10.5 in four strains of laboratory mice. We found that phenotypic variation in the forebrain is highly correlated with that of the face during face formation such that variation in the size of the forebrain correlates with the degree of prognathism and orientation of the facial prominences. This suggests strongly that the integration of the brain and face is relevant to the etiology of midfacial malformations such as orofacial clefts. This axis of integration also has important implications for the evolutionary developmental biology of the mammalian craniofacial complex.

Developmental and genetic origins of murine long bone length variation.

If we wish to understand whether development influences the rate or direction of morphological evolution, we must first understand the developmental bases of morphological variation within species. However, quantitative variation in adult morphology is the product of molecular and cellular processes unfolding from embryonic development through juvenile growth to maturity. The Atchley-Hall model provides a useful framework for dissecting complex morphologies into their component parts as a way of determining which developmental processes contribute to variation in adult form. We have examined differences in postnatal allometry and the patterns of genetic correlation between age-specific traits for ten recombinant inbred strains of mice generated from an intercross of LG/J and SM/J. Long bone length is closely tied to body size, but variation in adult morphology is more closely tied to differences in growth rate between 3 and 5 weeks of age. These analyses show that variation generated during early development is overridden by variation generated later in life. To more precisely determine the cellular processes generating this variation we then examined the cellular dynamics of long bone growth plates at the time of maximum elongation rate differences in the parent strains. Our analyses revealed that variation in long bone length is the result of faster elongation rates of the LG/J stain. The developmental bases for these differences in growth rate involve the rate of cell division and chondrocyte hypertrophy in the growth plate.

Inhaled aerosol particle dosimetry in mice: a review.

The availability of molecular and genetic tools has made the mouse the most common animal model for a variety of human diseases in toxicology studies. However, little is known about the factors that will influence the dose delivery to murine lungs during an inhalation study. Among these factors are the respiratory tract anatomy, lung physiology, and clearance characteristics. Therefore, the objective of this paper is to briefly review the current knowledge on the aforementioned factors in mice and their implications to the dose delivered to mouse models during inhalation studies. Representative scientific publications were chosen from searches using the NCBI PubMed and ISI Web of Knowledge databases. Relevant respiratory physiological differences have been widely reported for different mouse strains and sexes. The limited data on anatomical morphometry that is available for the murine respiratory tract indicates significant differences between mouse strains. These differences have implications to the dose delivered and the biological outcomes of inhalation studies.

Identification of a Chr 11 quantitative trait locus that modulates proliferation in the rostral migratory stream of the adult mouse brain.

Neuron production takes place continuously in the rostral migratory stream (RMS) of the adult mammalian brain. The molecular mechanisms that regulate progenitor cell division and differentiation in the RMS remain largely unknown. Here, we surveyed the mouse genome in an unbiased manner to identify candidate gene loci that regulate proliferation in the adult RMS. We quantified neurogenesis in adult C57BL/6J and A/J mice, and 27 recombinant inbred lines derived from those parental strains. We showed that the A/J RMS had greater numbers of bromodeoxyuridine-labeled cells than that of C57BL/6J mice with similar cell cycle parameters, indicating that the differences in the number of bromodeoxyuridine-positive cells reflected the number of proliferating cells between the strains. AXB and BXA recombinant inbred strains demonstrated even greater variation in the numbers of proliferating cells. Genome-wide mapping of this trait revealed that chromosome 11 harbors a significant quantitative trait locus at 116.75 +/- 0.75 Mb that affects cell proliferation in the adult RMS. The genomic regions that influence RMS proliferation did not overlap with genomic regions regulating proliferation in the adult subgranular zone of the hippocampal dentate gyrus. On the contrary, a different, suggestive locus that modulates cell proliferation in the subgranular zone was mapped to chromosome 3 at 102 +/- 7 Mb. A subset of genes in the chromosome 11 quantitative trait locus region is associated with neurogenesis and cell proliferation. Our findings provide new insights into the genetic control of neural proliferation and an excellent starting point to identify genes critical to this process.

[Comparative ultrastructural study of parotid gland, lacrimal gland and pituitary gland between miniature pig and mouse].

OBJECTIVE: To study the ultrastructure of parotid glands, lacrimal glands and pituitary glands between miniature pig and mouse. METHODS: Five adult miniature pigs and 5 mice were studied. Ultrastructure of their parotid glands, lacrimal glands, and pituitary glands was observed. RESULTS: The secretary granules in acinar cell of miniature pig parotid glands showed higher density and more aequalis than those of mice. The cell apparatus in acinar cell of mouse parotid glands were more plentiful than those of miniature pigs. The secretary granules on blood vessel wall were richer in parotid gland of miniature pigs compared with mouse parotid gland. Lacrimal gland had the similar ultrastructure to parotid gland in these two animals. Many blood vessel antrum were found in pituitary glands of these two animals. CONCLUSIONS: Compared with mouse parotid glands, there are more secretary granules in acinar cells and vascular endothelial cells in miniature pig parotid glands, which might enter blood stream and have function of endocrine secretion.

A comparison of covariance structure in wild and laboratory muroid crania.

Mutations have the ability to produce dramatic changes to covariance structure by altering the variance of covariance-generating developmental processes. Several evolutionary mechanisms exist that may be acting interdependently to stabilize covariance structure, despite this developmental potential for variation within species. We explore covariance structure in the crania of laboratory mouse mutants exhibiting mild-to-significant developmental perturbations of the cranium, and contrast it with covariance structure in related wild muroid taxa. Phenotypic covariance structure is conserved among wild muroidea, but highly variable and mutation-dependent within the laboratory group. We show that covariance structures in natural populations of related species occupy a more restricted portion of covariance structure space than do the covariance structures resulting from single mutations of significant effect or the almost nonexistent genetic differences that separate inbred mouse strains. Our results suggest that developmental constraint is not the primary mechanism acting to stabilize covariance structure, and imply a more important role for other mechanisms.

Mouse phenome database.

The Mouse Phenome Database (MPD; http://www.jax.org/phenome) is an open source, web-based repository of phenotypic and genotypic data on commonly used and genetically diverse inbred strains of mice and their derivatives. MPD is also a facility for query, analysis and in silico hypothesis testing. Currently MPD contains about 1400 phenotypic measurements contributed by research teams worldwide, including phenotypes relevant to human health such as cancer susceptibility, aging, obesity, susceptibility to infectious diseases, atherosclerosis, blood disorders and neurosensory disorders. Electronic access to centralized strain data enables investigators to select optimal strains for many systems-based research applications, including physiological studies, drug and toxicology testing, modeling disease processes and complex trait analysis. The ability to select strains for specific research applications by accessing existing phenotype data can bypass the need to (re)characterize strains, precluding major investments of time and resources. This functionality, in turn, accelerates research and leverages existing community resources. Since our last NAR reporting in 2007, MPD has added more community-contributed data covering more phenotypic domains and implemented several new tools and features, including a new interactive Tool Demo available through the MPD homepage (quick link: http://phenome.jax.org/phenome/trytools).

Identification of multiple quantitative trait loci affecting the size and shape of the mandible in mice.

A quantitative trait locus (QTL) analysis was performed on the size and shape of the mandible in F(2) mice between KK-A ( y ) and C57BL/6 J strains and the effect of the A ( y ) allele on the morphology of the mandible was analyzed. A total of 13 measurements were taken on each right mandible. By means of discriminant and canonical discriminant analyses, KK-A ( y ) males and KK males were exactly discriminated from each other. In contrast to its known effects on body weight, the A ( y ) allele reduced the overall size of the mandible. QTL analysis of the 13 measurements and on three principal components extracted from these measurements identified multiple QTLs. When F(2) a/a and F(2) A ( y )/a were analyzed separately, 11 significant main-effect QTLs were identified in F(2) a/a, whereas only two QTLs were identified in F(2) A ( y )/a. Although four significant interactions were identified, all were in F(2) a/a. The A ( y ) allele thus made the difference in the size and shape of the mandible between strains obscure. Among mandible QTLs, those on Chrs 5 (Mssq6 and Mssq7) and 15 (Mssq14) were important. Mssq6 had an effect on the height of the posterior mandible. Mssq7 had an effect on mandible length. Mssq14 had an effect on the height of the anterior and posterior mandible. Mssq7 and Mssq14 also had an effect on the overall size. Thus, mandible QTLs have distinct and characteristic sites of action. Therefore, mandible morphology will be determined largely by the combination of these QTLs.

The bite-raised condition enhances the aging process in the dorsal and ventral hippocampus.

The bite raised condition decreases the number of neurons and increases the amount of glial fibrillary acidic protein in the hippocampus of aged SAMP8 mice. In the present study, we examined whether these effects differ between the dorsal and ventral hippocampus. In bite-raised SAMP8 mice, the number of neurons was significantly lower in the hippocampal CA1 and dentate gyrus (DG) subfields compared to control mice. In the bite raised condition, the number of neurons was significantly lower in both the dorsal and ventral CA3 subfields, and the number of glial fibrillary acidic protein-labeled astrocytes was increased in the CA1, CA3, and DG subfields, compared to control mice. These data suggest that in aged SAMP8 mice, the bite-raised condition enhanced aging processes in both the dorsal and ventral hippocampus.

Cranial bone morphometric study among mouse strains.

BACKGROUND: Little is known about the molecular mechanism which regulates how the whole cranium is shaped. Mouse models currently available for genetic research include several hundreds of unique inbred strains and genetically engineered mutants. By cross comparing their genomic structures, we can elucidate the cause of any differences in the phenotype between two strains. The craniometry of subspecies, or closely related species, of mice provide a good systemic model to study the relationship between genetic variance and cranial shape evolution. The lack of a quantified framework for comparing and analyzing mouse cranial shape has been a problem. For this reason, we performed quantitative analysis of cranial shape morphology between several mouse strains. RESULTS: This article reports on a craniometric assay of seven mouse strains: four inbred strains (C57BL/6J, BALB/cA, C3H/HeJ, and CBA/JNCr) from Mus musculus domesticus (M. m. domesticus); one closed colony strain (ICR) from M. m. domesticus; one inbred strain (MSM/Ms) from Mus musculus molossinus; and, Mus spretus as a strain from a species other than M. m. domesticus. We performed linear measurements and geometric morphometrics. Geometric morphometrics revealed that the cranial characteristics of each strains were clearly distinguishable. We obtained mean scores for each species using the tpsRelw Program and plotted them. CONCLUSION: Geometric morphometrics proved to be useful for identifying and classifying variations in form, and it revealed that M. spretus has a slender cranium when compared with our other strains. The mean cranial shape of C3H or CBA was more similar to MSM/Ms, which is derived from M. m. molossinus, than to either C57BL/6J, BALB, or ICR which are derived from M. m. domesticus. Future work in this field will aid in elucidating the mechanism of whole cranial shape regulation.

The relative importance of genetics and phenotypic plasticity in dictating bone morphology and mechanics in aged mice: evidence from an artificial selection experiment.

Both genetic and environmental factors are known to influence the structure of bone, contributing to its mechanical behavior during, and adaptive response to, loading. We introduce a novel approach to simultaneously address the genetically mediated, exercise-related effects on bone morphometrics and strength, using mice that had been selectively bred for high levels of voluntary wheel running (16 generations). Female mice from high running and control lines were either allowed (n=12, 12, respectively) or denied (n=11, 12, respectively) access to wheels for 20 months. Femoral shaft, neck, and head were measured with calipers and via micro-computed tomography. Fracture characteristics of the femoral head were assessed in cantilever bending. After adjusting for variation in body mass by two-way analysis of covariance, distal width of the femur increased as a result of selective breeding, and mediolateral femoral diameter was reduced by wheel access. Cross-sectional area of the femoral mid-shaft showed a significant linetype x activity effect, increasing with wheel access in high-running lines but decreasing in control lines. Body mass was significantly positively correlated with many of the morphometric traits studied. Fracture load of the femoral neck was strongly positively predicted by morphometric traits of the femoral neck (r2>0.30), but no significant effects of selective breeding or wheel access were found. The significant correlations of body mass with femoral morphometric traits underscore the importance of controlling for body size when analyzing the response of bone size and shape to experimental treatments. After controlling for body mass, measures of the femoral neck remain significant predictors of femoral neck strength.

Genetic analysis of posterior medial barrel subfield (PMBSF) size in somatosensory cortex (SI) in recombinant inbred strains of mice.

BACKGROUND: Quantitative trait locus (QTL) mapping is an important tool for identifying potential candidate genes linked to complex traits. QTL mapping has been used to identify genes associated with cytoarchitecture, cell number, brain size, and brain volume. Previously, QTL mapping was utilized to examine variation of barrel field size in the somatosensory cortex in a limited number of recombinant inbred (RI) strains of mice. In order to further elucidate the underlying natural variation in mouse primary somatosensory cortex, we measured the size of the posterior medial barrel subfield (PMBSF), associated with the representation of the large mystacial vibrissae, in an expanded sample set that included 42 BXD RI strains, two parental strains (C57BL/6J and DBA/2J), and one F1 strain (B6D2F1). Cytochrome oxidase labeling was used to visualize barrels within the PMBSF. RESULTS: We observed a 33% difference between the largest and smallest BXD RI strains with continuous variation in-between. Using QTL linkage analysis from WebQTL, we generated linkage maps of raw total PMBSF and brain weight adjusted total PMBSF areas. After removing the effects of brain weight, we detected a suggestive QTL (likelihood ratio statistic [LRS]: 14.20) on the proximal arm of chromosome 4. Candidate genes under the suggestive QTL peak for PMBSF area were selected based on the number of single nucleotide polymorphisms (SNPs) present and the biological relevance of each gene. Among the candidate genes are Car8 and Rab2. More importantly, mRNA expression profiles obtained using GeneNetwork indicated a strong correlation between total PMBSF area and two genes (Adcy1 and Gap43) known to be important in mouse cortex development. GAP43 has been shown to be critical during neurodevelopment of the somatosensory cortex, while knockout Adcy1 mice have disrupted barrel field patterns. CONCLUSION: We detected a novel suggestive QTL on chromosome 4 that is linked to PMBSF size. The present study is an important step towards identifying genes underlying the size and possible development of cortical structures.

Phenotypic analysis of C57BL/6J and FVB/NJ mice generated using evaporatively dried spermatozoa.

Combination of evaporative drying and frozen storage at -80 degrees C has been used successfully to preserve hybrid B6D2F1 mouse spermatozoa. To determine whether this method can be applied equally well to inbred mice, spermatozoa of C57BL/6J and FVB/ NJ mice were evaporatively dried and stored for 1 mo at -80 degrees C before being used for intracytoplasmic sperm injection (ICSI) to produce live offspring. After weaning, 1 male and 1 female mouse from each litter were randomly selected at 8 wk of age for natural mating to produce live offspring. Results showed that spermatozoa from both inbred strains that had been evaporatively dried and subsequently stored at -80 degrees C could be used successfully to derive live, healthy, and reproductively sound offspring by ICSI. No significant differences were found in embryo transfer rate (number of pups born/number of embryos transferred), litter size, weaning rate, body weight, number of pathologic lesions, and amount of contamination by pathogens of mice produced by ICSI using evaporatively dried spermatozoa compared with mice produced by natural mating or by ICSI using fresh (that is, nonpreserved) spermatozoa. Progeny produced by mating mice generated from ICSI using evaporatively dried spermatozoa were normal. Therefore, spermatozoa from inbred mouse strains C57BL/6J and FVB/NJ can be preserved successfully after evaporative drying and frozen storage at -80 degrees C.