CXCR4(+)-targeted protein nanoparticles produced in the food-grade bacterium Lactococcus lactis

Lactococcus lactis is a Gram-positive (endotoxin-free) food-grade bacteria exploited as alternative to Escherichia coli for recombinant protein production. We have explored here for the first time the ability of this platform as producer of complex, self-assembling protein materials. Materials & methods: Biophysical properties, cell penetrability and in vivo biodistribution upon systemic administration of tumor-targeted protein nanoparticles produced in L. lactis have been compared with the equivalent material produced in E. coli. Results: Protein nanoparticles have been efficiently produced in L. lactis, showing the desired size, internalization properties and biodistribution. Conclusion: In vitro and in vivo data confirm the potential and robustness of the production platform, pointing out L. lactis as a fascinating cell factory for the biofabrication of protein materials intended for therapeutic applications.Award-winningPostprint (published version

The silent cattle breeders in central Nicaragua

Peer Revie

Sustainable milk and beef production in Nicaragua: actions and opportunities for an inclusive value chain

In Nicaragua the cattle sector accounts for 36% of agricultural exports and presents an important opportunity for smallholder farmer livelihoods. Current extensive dual-purpose (milk and beef) cattle production leads to soil degradation, deforestation, high levels of greenhouse gas (GHG) emissions per unit of product, and a shift of the agricultural frontier towards the vulnerable Caribbean region. The CGIAR Research Program on Livestock and Fish is implementing activities to make the dual-purpose cattle value chain more efficient, competitive and inclusive, with a specific focus on gender equality. Feed and forages work has improved the productivity of forage-based livestock production (up to 100% in terms of kg milk/ha), increased carbon accumulation and at the same time reduced its ecological footprint (by over 50% in terms of GHG emissions per unit of product) as part of LivestockPlus. This concept addresses sustainable intensification in three ways: socioeconomic – market opportunities and policy application; ecological – improved farm and natural resource management practices; and genetic – improved forage cultivars. Work on genetic improvement of cattle has included establishing an information, input, and service data platform linked to breed improvement in a wider farm-household context. It involves continuous monitoring and assessment of the performance of the predominant breed-types reared by 155 farmers in central Nicaragua as an initial step towards informing development of breeding strategies for dual purpose cattle in mixed farming systems. In collaboration with a farmers cooperative, capacity development in Farmer Field Schools and on-farm research involving 1000 farmers has resulted in increased productivity (milk by 40%, liveweight by 70%), income (by 20%) and natural resource integrity (establishment of 4,000 ha of silvopastoral systems). Strategic alliances have been developed between value chain actors (farmers' organisations, NGOs, research, private sector with a focus on value addition to livestock products while increasing gender equity. In general, however, adoption of improved technologies and practices is still low. There is therefore a strong need for an increased policy incidence on sustainable livestock development and incentive mechanisms for farmers and other value chain actors, including certification of sustainable livestock products

Dual-purpose cattle production in Nicaragua: Which breed fits best?

The importance of milk and beef production in Latin America is high and increasing. In Nicaragua and neighbouring countries, smallholder dual-purpose (i.e., milk and beef) cattle production offers opportunities for poor cattle owners to improve their food and nutrition security, and increase their income. The milk and beef value chain employs thousands of people in production, processing and marketing. In order to improve production, many farmers currently practice crossbreeding, involving a large range of breed combinations, but without clear breeding strategies. To assess current farmers´ practices and develop appropriate breeding and related management recommendations, a research project that brings together the national agricultural university of Nicaragua (UNA), the International Livestock Research Institute (ILRI), the International Center for Tropical Agriculture (CIAT and BOKU-University is being implemented in two study sites in Central Nicaragua, Camoapa and Matigu´as Municipalities. A gender-responsive baseline survey with questionnaires was performed with 289 households in Camoapa and 252 in Matigu´as, using a random sampling procedure based on official census data. A “paperless” data collection format was adopted using the “Open Data Kit” (ODK) information technology platform. Most households (>83 %) were male-headed in both municipalities. Mean age of the household head was higher in Camoapa (51.4±14 years) than in Matiguas (48.9±14 years). Most of the cattle reared in the two municipalities were cross-breds (>98 %). The crosses comprised combinations between several breed-types. The most abundant breed-type in Matigu´as was the Brahman, while in Camoapa there were more Brown Swiss and Holstein cross animals. At both locations also other breeds such as Creole, Girolando, Jersey, Nellore, Reyna and Simmental were found, whereas a large proportion of animals were crosses of unknown breed-types. Farmers stated different reasons for using various breeds in their herds such as availability of semen or bulls or different purposes for production. This is also reflected in the selection criteria of farmers. In comparison to Matigu´as, cattle production in Camoapa is more intensive (higher number of animals per hectare, stronger tendency towards dairy production), this probably being an effect of a stronger presence of development organisations

Integrating gender analysis in understanding dual-purpose cattle breeding practices in Nicaragua

Dual purpose cattle production in mixed farming systems of Nicaragua is predominantly based on permanent grazing of naturalized grasslands, introduced pastures and crop residues. Milk production and animal offtake rates are low. Information to guide gender responsive interventions to improve livestock production is being generated through a collaborative project by the International Livestock Research Institute (ILRI), the International Center for Tropical Agriculture (CIAT), the National Agrarian University of Nicaragua (UNA), and the University of Natural Resources and life Sciences in Austria (BOKU). Gender disaggregated data on milk production of 447 animals on 59 farms from Camoapa in central Nicaragua have been collected over 8 months. The data shows that more than 40% of the households keep Brown Swiss crosses, however, male headed households keep significantly more Brahman and Holstein crosses than female headed households. The average daily milk production per animal is also significantly lower in female headed households (3.54±1.55kg) than in male headed households (4.14 ±1.87kg). Farmers are conversant with Artificial Insemination (AI), however the technology is not widely adopted. Reasons mentioned for low adoption include: high costs of service, need for repeat services, and unavailability of semen from desired breed-types (e.g. Brahman × Brown Swiss). Gender analysis revealed that the need for repeated services, which increased the costs of AI, is caused by a time mismatch between the animals' heat and the AI provision. These delays are in turn determined by the gender division of labour in livestock management: women are in charge of identifying when animals come into heat but have to wait for the men to call the AI service providers. Women head of households have difficulty accessing AI services and information altogether as they are less involved in cooperative groups and training on technologies related to cattle production. This reduces the effectiveness of AI in both male and female headed households. Practical training programs are required on reproductive management and the use of AI designed with gender responsive approaches

Heterokaryon Incompatibility Is Suppressed Following Conidial Anastomosis Tube Fusion in a Fungal Plant Pathogen

It has been hypothesized that horizontal gene/chromosome transfer and parasexual recombination following hyphal fusion between different strains may contribute to the emergence of wide genetic variability in plant pathogenic and other fungi. However, the significance of vegetative (heterokaryon) incompatibility responses, which commonly result in cell death, in preventing these processes is not known. In this study, we have assessed this issue following different types of hyphal fusion during colony initiation and in the mature colony. We used vegetatively compatible and incompatible strains of the common bean pathogen Colletotrichum lindemuthianum in which nuclei were labelled with either a green or red fluorescent protein in order to microscopically monitor the fates of nuclei and heterokaryotic cells following hyphal fusion. As opposed to fusion of hyphae in mature colonies that resulted in cell death within 3 h, fusions by conidial anastomosis tubes (CAT) between two incompatible strains during colony initiation did not induce the vegetative incompatibility response. Instead, fused conidia and germlings survived and formed heterokaryotic colonies that in turn produced uninucleate conidia that germinated to form colonies with phenotypic features different to those of either parental strain. Our results demonstrate that the vegetative incompatibility response is suppressed during colony initiation in C. lindemuthianum. Thus, CAT fusion may allow asexual fungi to increase their genetic diversity, and to acquire new pathogenic traits

X chromosome inactivation does not necessarily determine the severity of the phenotype in Rett syndrome patients

Rett syndrome (RTT) is a severe neurological disorder usually caused by mutations in the MECP2 gene. Since the MECP2 gene is located on the X chromosome, X chromosome inactivation (XCI) could play a role in the wide range of phenotypic variation of RTT patients; however, classical methylation-based protocols to evaluate XCI could not determine whether the preferentially inactivated X chromosome carried the mutant or the wild-type allele. Therefore, we developed an allele-specific methylation-based assay to evaluate methylation at the loci of several recurrent MECP2 mutations. We analyzed the XCI patterns in the blood of 174 RTT patients, but we did not find a clear correlation between XCI and the clinical presentation. We also compared XCI in blood and brain cortex samples of two patients and found differences between XCI patterns in these tissues. However, RTT mainly being a neurological disease complicates the establishment of a correlation between the XCI in blood and the clinical presentation of the patients. Furthermore, we analyzed MECP2 transcript levels and found differences from the expected levels according to XCI. Many factors other than XCI could affect the RTT phenotype, which in combination could influence the clinical presentation of RTT patients to a greater extent than slight variations in the XCI pattern

Population structure and phenotypic characterization as a basis for conservation and sustainable use of Reyna Creole Cattle in Nicaragua

The Reyna Creole cattle in Nicaragua is a local breed originating from the Bos taurus cattle brought to Latin America during the Spanish colonization in the fifteenth century. Reyna Creole cattle are today found in five herds. The primary use of the breed is to produce milk. The breed comprises about 650 purebred female animals. The main objective of the thesis was to characterize the population structure and productivity in terms of milk production and some reproduction traits, and to discuss options for conservation and improvement of the breed. The inbreeding level was 13% on average, primarily due to use of individual bulls for long periods. An effective population size of 28 to 46 animals was estimated, showing that the Reyna Creole cattle breed is endangered, close to critical status. Average birth weight was 27.8 kg, age at first calving 37.4 months and calving interval 14.0 months. Large differences between herds were observed for all traits. Heritabilities were 0.34, zero and 0.20 for the respective trait. Average lactation yield for 534 Reyna cows with 1,750 lactations was 1,319 kg with large variations between herds and time periods. Test-day records on milk yield and fat and protein contents were collected monthly during one year for three Reyna herds and two herds with crossbred cows. Commercial dairy breed crosses had the highest production, and Reyna the lowest, but large differences were noted in management between the herds. The heritability for lactation yield in Reyna cattle was 0.18. Large variation between and within the Reyna herds suggest good opportunities to increase productivity of the Reyna breed by improving management and breeding strategies. It is proposed to keep all females in the herds, develop mating plans and to apply a recording scheme for keeping pedigrees and records on reproduction and milk production traits. Only young bulls, selected from the best cows for milk production and calving interval, are proposed to be used for 1-2 years each to manage inbreeding and keep generation intervals short