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The CRISPR-Cas9 system provides the ability to edit, repress, activate, or mark any gene (or DNA element) by pairing of a programmable single guide RNA (sgRNA) with a complementary sequence on the DNA target. Here we present a new method for small-molecule control of CRISPR-Cas9 function through insertion of RNA aptamers into the sgRNA. We show that CRISPR-Cas9-based gene repression (CRISPRi) can be either activated or deactivated in a dose-dependent fashion over a >10-fold dynamic range in response to two different small-molecule ligands. Since our system acts directly on each target-specific sgRNA, it enables new applications that require differential and opposing temporal control of multiple genes.

Modeling and analysis of complex biological networks presents a number of mathematical challenges. For the models to be useful,from a biological standpoint, then, must be systematically compared with data. Robustness is a key to biological understanding and proper feedback to guide experiments, including both the deterministic stability and performance properties of models in the presence of parametric uncertainties and their stochastic behavior in the presence of noise. In this paper, we present mathematical and algorithmic tools to address such questions for models that may be nonlinear hybrid, and stochastic. These tools are rooted in solid mathematical theories, primarily from robust control and dynamical systems, but with important recent developments. They also have the potential for great practical relevance, which we explore through a series of biologically motivated examples.

Six divergent cotton genotypes were crossed in un-constructed to be 15 F1 crosses then, F2 were obtained. All genotypes were evaluated in Randomized Complete Block Design with three replicates. Genetic parameters of natural performance of genes were estimated by Hayman method (1954) for characters of Boll weight (B.W.), Seed cotton yield (S.C.Y.), Lint yield (L.Y.), Seed index (S.I.), Lint percentage (L. %), Lint index (L.I.) and oil%. The result showed that additive and dominance variance H1 and H2 values were significant for all traits, and the additive values were less from dominant values, that refers to the importance of dominance variance in its inheritance. Also, the H2 values were less than H1 which recorded that the allelic frequencies were not equal. The overall dominance effects of heterozygous loci (h² ) were significant for all traits in both generations, indicating that the dominance was due to heterozygosity and was unidirectional with appreciable heterotic effect. The proportion of dominant to recessive gene in parents KD/KR were more than unity for most studied traits. The average degree of dominance (H1/D)0.5 exceeded unity for all studied traits in both generations, indicating that presence of over dominance for these traits. High values for heritability in broad sense were obtained for all traits, revealing that most phenotypic variability in each trait was due to genetic causes. High heritability values in broad sense along with medium or low ones in narrow sense were exhibited in both generations, indicating that most genetic variances were due to non-additive genetic effects. The regression line passed through the origin in boll weight in generations, seed index, lint percentage and oil% in F1, revealed a presence of complete dominance. Meanwhile, it intersects the Wr axis above the origin in lint yield and oil% in F2, reflecting partial dominance. The P4, p2, P2, P5, P5, P2 and P5 in F1, P4, P2, P1, P5, P6, P3 and P6 in F2 for B.W., S.C.Y., L.Y., S.I., L. %, L.I and oil%, respectively seemed to have the highest number of dominant genes. [ABSTRACT FROM AUTHOR]

Heterosis and gene action on oil%, and yield traits were determined in a 6x6 diallel cross of cotton without reciprocals and their F2 generation to define and select an efficient and prospective material for immediate use in hybridization programs to improve seed yield of cotton in Egypt. Parents, F1 and F2 were evaluated in a randomized complete block design (RCBD) with three replicates for yield traits in 2021 season. High significant mean squares for genotype, parents and crosses were showed for the studied traits in both generations. Significant heterosis in F1 generation was obtained for all studied traits. The desirable heterosis of relative to better parent varied from 5.36 to 25.29, 5.92 to 33, 2.3 to 5.89 and 1.14 to 7.38 in F1 generation for seed cotton yield, lint yield, seed index and oil%, respectively. The cross P2xP3 was the best cross for all studied traits heterosis. Mean squares for general (GCA) and specific (SCA) combining ability were significant for all studied traits. MS (GCA)/ MS (SCA) ratios displays the relative importance of additive and additive by additive gene action effects in their inheritance for seed cotton yield, lint yield, seed index and lint percentage in F1 generation and seed cotton yield and lint yield in F2 generation. P1 exhibited significant desirable ĝi effect among all the tested parents for lint percentage, lint index and oil% in F1 and seed cotton yield, lint yield and oil % in F2. The cross P2xP3 showed significantly desirable SCA effects for most studied traits. [ABSTRACT FROM AUTHOR]

The present work has been performed to study the growth and metabolic activities of maize and broad bean plants which are shown to have a degree of sensitivity to salinity and to determine the role of amino acids proline or phenylalanine in increasing the salt tolerance of theses plants. Dry mass, water content, leaf area and photosynthetic pigment of maize and broad bean plants decreased with increasing salinity. These changes were accompanied with a drop in the contents of soluble sugars, soluble proteins and amino acids. This was accompanied by a marked increase in the proline content. When maize and broad bean plants sprayed with proline or phenylalanine the opposite effect was occurred, saccharides as well as proteins progressively increased at all sanitization levels and proline concentration significantly declined. Salinity significantly increased the sodium content in both shoots and roots of maize and broad bean plants, while a decline in the accumulation of K+, Ca++, Mg++ and P was observed. Amino acids treatments markedlyaltered the selectivity of Na+, K+, Ca++ and P in both maize and broad bean plants. Spraying with any of either proline orphenylalanine restricted Na+ uptake and enhanced the uptake of K+, K+/Na+ ratio, Ca++ and P selectivity in maize and broad bean plants.

Actinomycosis, or lumpy jaw, is an important cause of economic losses in livestock because of its widespread occurrence and poor response to the routine clinical treatment. The present study describes a typical case of bovine actinomycosis in a seven-month pregnant Sahiwal heifer with a hard swelling on the middle of the maxilla bone at the level of the central molar teeth. Tentative diagnosis was made through clinical signs. After maturation of the swelling, the area was incised under local anesthesia and debridement of the wound was achieved by sharp surgical debridement and mechanical debridement. Pus, having the appearance of sulphur granules, was completely removed from the excised cavity, which was closed by applying mattress sutures. Adjunct therapy of broad-spectrum antibiotic was administered intramuscularly for five days as a post-operative measure. Catamnesis revealed that the healing was complete in 15 days with no recurrence and untoward consequences.

This study was designed to evaluate the efficacy of different somatic cell types and media in supporting in vitro maturation (IVM), in vitro fertilization (IVF) and early embryonic development competence of buffalo follicular oocytes. Cumulus oocyte complexes were collected for maturation from follicles (>6mm) of buffalo ovaries collected at the local abattoir. Oocytes were co-cultured in tissue culture medium (TCM-199) with either granulosa cells, cumulus cells, or buffalo oviductal epithelial 6 cells (BOEC) @ 3x106 cells/ml or in TCM-199 without helper cells (control) at 39°C and 5% CO2 in humidified air. Fresh semen was prepared in modified Ca++ free Tyrode medium. Fertilization was carried out in four types of media: i) Tyrode lactate albumin pyruvate (TALP), ii) TALP+BOEC, iii) modified Ca++ free Tyrode and iv) modified Ca free Tyrode+BOEC. Fertilized oocytes were cultured for early embryonic development in TCM-199 with and without BOEC. Higher maturation rates were observed in the granulosa (84.24%) and cumulus cells (83.44%) than BOEC co culture system (73.37%). Highest fertilization rate was obtained in modified Ca++ free Tyrode with BOEC co culture (70.42%), followed by modified Ca free Tyrode alone (63.77%), TALP with BOEC (36.92%) and TALP alone (10.94%). Development of early embryos (8-cell stage) improved in TCM- 199 with BOEC co culture than TCM-199 alone. From the results of this study, it can be concluded that addition of somatic cells (granulosa cells, cumulus cells) results in higher maturation rates of buffalo follicular oocytes than BOEC co culture system, while fertilization rate improved in modified Ca++ free Tyrode with and without BOEC. Addition of BOEC to TCM-199 improved the developmental capacity of early embryo. [ABSTRACT FROM AUTHOR]

Cholistan, once a green and prosperous land with the source of water being the ancient Hakra River, was also the cradle of great Hakra Valley Civilization. It is sprawled at an area of 26,000 Km2, located between the latitudes 27°42'and 29°45' North and longitudes 69°52' and 75°24' East. The bioclimatic system of Cholistan falls under the category of "tropical desert" with very scanty rainfall. Geomorphologically, the soils of Cholistan are a complex blend of river alluvium and Aeolin sands. Based on topography, type of soil and vegetation, this desert is divided into two geomorphic regions: the Lesser Cholistan (the Northern 7,770 Km2 region) and the Greater Cholistan (the Southern 18,130 Km2 region). The primary source of water is rainfall which is utilized through natural depressions or man-made ponds called "Tobas" and "Dahars." The secondary source is underground water which is brackish and salty and not fit for human/animal consumption. Two livestock production systems prevail under pastoralism in Cholistan viz. transhumanie and nomadic. Despite an uncertain, unpredictable rainfall, low humidity and extremes in temperatures, Cholistan has long been famous for raising different breeds of livestock, contributing a significant share to national milk, meat and wool output. The total livestock population estimated during 2006 was 12,09528, out of which 47% were cattle. Cholistani cattle are considered to be ancestor of the Sahiwal and are a thermo-tolerant, tick-resistant breed. Preliminary data on some productive and reproductive traits of Cholistani cows maintained at Govt. Livestock Station, Jugait Peer, Bahawalpur during the period 2005 to 2009 revealed the avergae values for the productive traits i.e. lactation length, lactation yield, dry period, service period and fat percentage in milk as 165 days, 1235 liters, 155 days, 121 days and 4.8%, respectively. Similarly, the average values for reproductive traits i.e. age at maturity, age at first calving, gestation period and calving interval were 1112, 1390, 278 and 422 days, respectively, which are at par with those of Sahiwal and Red Sindhi cattle. However, comprehensive data supported by research need to be analyzed to manipulate the potentials of this breed. Furthermore, gene mapping and Marker Assisted Selection (MAS) will open up new horizons to study performance traits of Cholistani cattle in detail. [ABSTRACT FROM AUTHOR]