Lactoferrin interaction with retinoid signaling: cell growth and apoptosis in mammary cells

Lactoferrin (Lf) is a multifunctional iron-binding protein that was first identified in mammary secretions, but is synthesized by most mammalian tissues. The protein has a signal sequence that dictates secretion; it also has a nuclear localization sequence that facilitates entry into the cell nucleus. The mechanism of the latter action is currently unknown, but is thought to occur via a Lf receptor. Lactoferrin content of mammary tissue and secretions varies with developmental state; it is synthesized in mammary tissue at high levels during both pregnancy and involution, and during mammary infections. Using fluorescent (FITC)-labeled holo-bLf, we show that bovine primary epithelial cells and MCF-7 breast cancer cells do not translocate the exogenously added Lf to the nucleus after culture in serum free media (SFM). However, the supplementation of SFM with 1 μM all-trans retinoic acid (atRA) caused breast cancer cells to gain the capacity to take up labeled bLf into the cell nucleus. Primary bovine mammary cells (MeBo) exhibited similar capacity in culture. This suggests that in addition to Lf, one or more components modulated by atRA, are necessary for nuclear translocation to occur. Transfection experiments with atRA treated MCF-7 cells containing retinoic acid response element reporter constructs showed that the extracellular application of lactoferrin alters reporter gene expression. Lactoferrin increased a DR5 luciferase response element in a dose-dependent manner only when atRA was applied. Immunocytochemical markers for the cell cycle (Ki67) and apoptotic events (Caspase-3 and PARP-85) showed that lactoferrin alters the atRA-induced phenotype, blocking apoptosis and maintaining cell cycle activity in both MCF-7 and MeBo cells in the presence of 1 μM atRA. We propose that nuclear lactoferrin interacts with retinoic acid signaling pathways in cells and alters/blocks the signals so that cells remain in the cell cycle and/or do not enter the apoptotic pathway.     

Characterization of Mongolian Gerbil Chromatoid Bodies and Their Correlation with Nucleolar Cycle During Spermatogenesis

The aims of the present study were to monitor the nucleolar cycle in Mongolian gerbil spermiogenesis, to verify the relationship between the nucleolar component and chromatoid body (CB) formation and to investigate the function of this cytoplasmic supramolecular structure in spermatogenic cells. Histological sections of adult seminiferous tubules were analysed cytochemically by light microscopy and ultrastructurally by transmission electron microscopy. The results reveal that in early spermatids, the CB was visualized in association with Golgi vesicles indicating that this structure may participate in the acrosome formation process as had been reported in other rodents. In late spermatids, the CB was observed near the axoneme region suggesting that this structure may support spermatozoon tail formation as happens in other species. Chromatoid body was joined with lipid droplets in this same cell type. This observation should be investigated to verify whether CB may be related to steroidal hormone metabolism. In conclusion, our data showed that there is disintegration of primary spermatocyte nucleoli at the beginning of prophase I and a fraction of this nucleolar material migrates to the cytoplasm, where a specific structure is formed, known as the ‘chromatoid body’, which apparently participates in some parts of the gerbil spermiogenesis process.     

Reproductive Patterns in the Non‐Breeding Season in Asinina de Miranda Jennies

This study aims to characterize the reproductive patterns in Asinina de Miranda jennies during the non‐breeding season. Reproductive activity was surveyed in 12 females, aged between 3 and 18 years old, using ultrasound and teasing with a jack. The animals were monitored from September to April, six in each consecutive year. Of these 12 females, nine showed disruption to the normal pattern of ovarian activity during the non‐breeding season. Loss of normal cyclicity included anoestrus (41.7%), silent ovulatory oestrus (25%), and persistence of corpus luteum (8.3%). Only three females maintained a regular cyclic pattern with oestrous behaviour during the non‐breeding season. Anoestrus began in early November and lasted for an average of 147 ± 28 days (113–191 days), ending near to the spring equinox. Onset of silent oestrous cycles began more erratically, between October and February. In both groups the first behavioural ovulation of the year occurred around the time of the spring equinox. Disrupted reproductive activity was preceded by a shorter oestrous cycle only in females entering anoestrus. The mean follicle size in the first ovulation of the year was larger than in the reproductive season (44.7 ± 2.45 mm vs 39.2 ± 3.60 mm) in anoestrous jennies with protracted oestrus. Though age and body condition score (BCS) were associated, changes in BCS below a threshold of four points (for anoestrus) and five points (for silent oestrus) contributed greatly to disruption of reproductive cycles. BCS in females with regular oestrous cycles during the winter season remained unchanged or exceeded five points prior to the winter solstice.     

Pb isotopic variability in melt inclusions from oceanic island basalts, polynesia

Previous studies have suggested that melting processes are responsible for the trace element variability observed in olivine-hosted basaltic melt inclusions. Melt inclusions from three individual lava samples (two from Mangaia, Cook Islands, and one from Tahaa, Society Islands) have heterogeneous Pb isotopic compositions, even though the erupted lavas are isotopically homogeneous. The range of Pb isotopic compositions from individual melt inclusions spans 50 percent of the worldwide range observed for ocean island basalts. The melt inclusion data can be explained by two-component mixing for each island. Our data imply that magmas with different isotopic compositions existed in the volcanic plumbing system before or during melt aggregation.     

Lactational traits of importance in dairy cows and applications for emerging biotechnologies

New molecular and quantitative genetic technologies are the latest in a long list of technologies that have been introduced to dairy industries over many decades to improve the performance of cows. The catalysts for future advances will be sequencing of the bovine genome and development of high-throughput technologies to identify and exploit relevant variation in DNA sequences. The new technologies will allow the selection of animals based on specific genotypes that suit specific applications such as once-daily (OAD) milking or extended lactation.

These technologies will also allow exploitation of between-cow variation in milk composition, which is currently hidden by bulking of milk on and between farms. Thus, there are opportunities to produce milk from herds of cows selected for specific milk composition that might be, for example, more suitable for cheese-making or have milkfat with specific properties to enhance human health. Identification of genes and gene polymorphisms associated with improved resistance to specific diseases in cows and other farm species also represents a real opportunity to improve animal health over the coming decade.

New levels of genetic regulation have been identified, e.g. microRNA and epigenetics, the impacts of which on the performance of cows and humans are only just beginning to be understood.

There is a potential role for veterinarians to provide or be the interface for provision of genetic advice to farmers in much the same way that nutritional advice is currently given.     

Serologic prevalence of caprine arthritis-encephalitis virus in California goat dairies

Fifty-three percent of goats in 13 California goat dairies had antibodies to caprine arthritis-encephalitis virus (CAEV), as determined by agar-gel immunodiffusion. Those goat dairies that reared kids on pasteurized milk had a lower seroprevalence than those that did not. Age, rearing kids on unpasteurized milk, and the presence of large joints were associated with antibodies to CAEV. Breed was associated with seroreactivity, but the association was confounded by other factors. Sex was not associated with antibodies to CAEV. The relationship between age and antibodies to CAEV was observed for goats reared on pasteurized or unpasteurized milk, which indicated that continued horizontal (contact) transmission may be important on these dairies and limited the effect of a pasteurized rearing program on control of CAEV infection.     

The Effect of Cyst Nematode Race 3 and Bradyrhizobium japonicum Interactions on Nodulation and Other Agronomic Characters of Three Soybean Genotypes

The effect of soybean cyst nematode (SCN) race 3 and strains of Bradyrhizobium japonkum interactions on nodulation and other agronomic characters of several soybean genotypes was investigated. Nodule weight was reduced in soybean cultivar Ogden treated with SCN plus Bradyrhizobia strains USDA 110 and 6 and on soybean cultivar Essex treated with SCN plus strain USDA 6. The result was reversed on soybean cultivar Essex treated with SCN plus strain USDA 110. The nodule number also decreased on soybean cultivars Ogden and Essex treated with SCN plus strains USDA 110 and 6. The fresh root weights of soybean cultivars Ogden and Essex treated with SCN plus strain USDA 110 were heavier than the fresh root weight of Essex treated with SCN plus strain USDA 6. Lower nitrogen content of stems and leaves was noted only in cultivar Essex treated with SCN plus strains USDA 110 and 6. Bradyrhizobia strain USDA 110 was more efficient in the initiation of nodules in cultivars Ogden and Essex than strain USDA 6. The nitrogen-fixing capacity of strain USDA 6 in Ogden was better than strain USDA 110. The differences in the agronomic performances of the various soybean genotypes were due to their degree of susceptibility to SCN and Bradyrhizobia strains and also to their genetic make-up.     

Occurrence of hepatocellular carcinoma in an adult male Nile lechwe (Kobus megaceros).

A 14-yr-old male Nile lechwe (Kobus megaceros) from the Jackson Zoo (Mississippi, USA) had chronic weight loss that was associated with elevated serum alkaline phosphatase levels. Approximately 4 yr after the first clinical signs of weight loss, the animal fractured its left rear femur and was subsequently euthanized; on the same day necropsy was performed. The liver was grossly enlarged and contained a smooth-surfaced nodular mass that occupied the majority of the right lobe of the liver. The mass had a liver-like appearance exhibiting a tan-red coloration but having a soft consistency. A single, approximately 0.6 cm, round, slightly elevated discrete red nodule was present in the left anterior lung. Microscopically, the hepatic mass and pulmonary nodule diffusely consisted of irregular cords of cells exhibiting hepatoid features, but containing no evidence of normal portal bile duct or portal triad development. To our knowledge, this is the first report in the scientific literature of a naturally occurring case of hepatocellular carcinoma in a Nile lechwe or in any antelope species.