Setback to and Encouragement of Feedback: Teacher and Student Perspectives

The research explored setback to, and encouragement of feedback as perceived by teachers and students. Three research questions guided the study. The population of the study constituted 180 teachers and 3200 students in government owned secondary schools in Ekwusigo L.G.A of Anambra State. Simple random sampling technique was used to draw the sample of teachers and students. Two questionnaires, one for teachers and one for students were used to collect data. Arithemetical mean was used in answering the research questions. The results revealed that all the stipulated factors constituted setbacks to teachers in giving feedback to their students. All the teachers indicated that all the listed items can encourage them in giving feedback to their students. Also, almost all the items except one constituted setback for the students in receiving feedback from their teachers. It was recommended that workload of teachers should be moderate, and the teacher should be relieved of other duties that may affect teaching and learning. Also, students’ seriousness should be boosted by ensuring that they repeat class when they fail among others.

Comparative Repeat Profiling of Two Closely Related Conifers (Larix decidua and Larix kaempferi) Reveals High Genome Similarity With Only Few Fast-Evolving Satellite DNAs

In eukaryotic genomes, cycles of repeat expansion and removal lead to large-scale genomic changes and propel organisms forward in evolution. However, in conifers, active repeat removal is thought to be limited, leading to expansions of their genomes, mostly exceeding 10 giga base pairs. As a result, conifer genomes are largely littered with fragmented and decayed repeats. Here, we aim to investigate how the repeat landscapes of two related conifers have diverged, given the conifers’ accumulative genome evolution mode. For this, we applied low-coverage sequencing and read clustering to the genomes of European and Japanese larch, Larix decidua (Lamb.) Carrière and Larix kaempferi (Mill.), that arose from a common ancestor, but are now geographically isolated. We found that both Larix species harbored largely similar repeat landscapes, especially regarding the transposable element content. To pin down possible genomic changes, we focused on the repeat class with the fastest sequence turnover: satellite DNAs (satDNAs). Using comparative bioinformatics, Southern, and fluorescent in situ hybridization, we reveal the satDNAs’ organizational patterns, their abundances, and chromosomal locations. Four out of the five identified satDNAs are widespread in the Larix genus, with two even present in the more distantly related Pseudotsuga and Abies genera. Unexpectedly, the EulaSat3 family was restricted to L. decidua and absent from L. kaempferi, indicating its evolutionarily young age. Taken together, our results exemplify how the accumulative genome evolution of conifers may limit the overall divergence of repeats after speciation, producing only few repeat-induced genomic novelties.

Natural genetic diversity in the potato resistance gene RB confers suppression avoidance from Phytophthora effector IPI-O4

RB is a potato gene that provides resistance to a broad spectrum of genotypes of the late blight pathogen Phytophthora infestans. RB belongs to the CC-NB-LRR (coiled-coil, nucleotide-binding, leucine-rich repeat) class of resistance (R) genes, a major component of the plant immune system. The RB protein detects the presence of Class I and II IPI-O effectors from P. infestans to initiate a hypersensitive resistance response, but this activity is suppressed in the presence of the Class III effector IPI-O4. Using natural genetic variation of RB within potato wild relatives, we identified two amino acids in the CC domain that alter interactions needed for suppression of resistance by IPI-O4. We have found that separate modification of these amino acids in RB can diminish or expand the resistance capability of this protein against P. infestans in both Nicotiana benthamiana and potato. Our results demonstrate that increased knowledge of the molecular mechanisms that determine resistance activation and R protein suppression by effectors can be utilized to tailor-engineer genes with the potential to provide increased durability.

Comparative repeat profiling of two closely related conifers (Larix decidua and Larix kaempferi) reveals high genome similarity with only few fast-evolving satellite DNAs

ABSTRACTIn eukaryotic genomes, cycles of repeat expansion and removal lead to large-scale genomic changes and propel organisms forward in evolution. However, in conifers, active repeat removal is thought to be limited, leading to expansions of their genomes, mostly exceeding 10 gigabasepairs. As a result, conifer genomes are largely littered with fragmented and decayed repeats. Here, we aim to investigate how the repeat landscapes of two related conifers have diverged, given the conifers’ accumulative genome evolution mode. For this, we applied low coverage sequencing and read clustering to the genomes of European and Japanese larch, Larix decidua (Lamb.) Carrière and Larix kaempferi (Mill.), that arose from a common ancestor, but are now geographically isolated. We found that both Larix species harbored largely similar repeat landscapes, especially regarding the transposable element content. To pin down possible genomic changes, we focused on the repeat class with the fastest sequence turnover: satellite DNAs (satDNAs). Using comparative bioinformatics, Southern, and fluorescent in situ hybridization, we reveal the satDNAs’ organizational patterns, their abundances, and chromosomal locations. Four out of the five identified satDNAs are widespread in the Larix genus, with two even present in the more distantly related Pseudotsuga and Abies genera. Unexpectedly, the EulaSat3 family was restricted to L. decidua and absent from L. kaempferi, indicating its evolutionarily young age. Taken together, our results exemplify how the accumulative genome evolution of conifers may limit the overall divergence of repeats after speciation, producing only few repeat-induced genomic novelties.

Heterochiasmy facilitated the establishment of gsdf as a novel sex determining gene in Atlantic halibut

Atlantic Halibut (Hippoglossus hippoglossus) has a X/Y genetic sex determination system, but the sex determining factor is not known. We produced a high-quality genome assembly and identified parts of chromosome 13 as the Y chromosome due to sequence divergence between sexes and segregation of sex genotypes in pedigrees. Linkage analysis revealed that all chromosomes exhibit heterochiasmy, i.e. male- and female restricted meiotic recombination intervals (MRR/FRR). We show that FRR/MRR intervals differ in nucleotide diversity and repeat class content and that this is true also for other Pleuronectidae species. We further show that remnants of a Gypsy-like transposable element insertion on chr13 promotes early male specific expression of gonadal somatic cell derived factor (gsdf). Less than 4 MYA, this male-determining element evolved on an autosomal FRR segment featuring pre-existing male meiotic recombination barriers, thereby creating a Y chromosome. We propose that heterochiasmy may facilitate the evolution of genetic sex determination systems.

Natural genetic diversity in the potato resistance gene RB confers suppression avoidance from Phytophthora effector IPI-O4

ABSTRACTRB is a potato gene that provides resistance to a broad spectrum of genotypes of the late blight pathogen Phytophthora infestans. RB belongs to the CC-NB-LRR (coiled-coil, nucleotide-binding, leucine-rich repeat) class of resistance (R) genes, a major component of the plant immune system. It directly interacts with Class I and II IPI-O effectors from P. infestans to initiate a hypersensitive resistance response, but this activity is suppressed in the presence of the Class III effector IPI-O4. Using natural genetic variation of RB within potato wild relatives, we identified two amino acids in the CC domain that alter interactions needed for suppression of resistance by IPI-O4. We have found that separate modification of these amino acids in RB can diminish or enhance the resistance capability of this protein against P. infestans in both Nicotiana benthamiana and potato. Our results demonstrate that increased knowledge of the molecular mechanisms that determine resistance activation and R protein suppression by effectors can be utilized to tailor-engineer genes with the potential to provide increased durability.

Islamic Guidance Model Case Study of New Students who Repeat Class at Madrasah Qudsiyyah Kudus

This study aims to describe how the Islamic guidance model is implemented at Madrasah Qudsiyyah. It is as part of the process of transforming the religious behavior of new students who repeat the class and how their religious behavior in the class. This study used a phenomenological approach with qualitative research method. Data were obtained through observation, interviews and documentation, then analyzed and concluded. The results of this study indicate that the students who repeat at Madrasah Qudsiyyah are new students who based on the entry selection test, their abilities are below the average so they must repeat in fifth or sixth grade of MI. Even though they have graduated from SD or MI in previous schools, as well as when they enter the Aliyah level, most of them will repeat in ninth grade of MTs Qudsiyyah. habituation. Using this way, the teachers succeeded in changing the santri attitude to be more enthusiastic, optimistic, <em>istiqamah</em> and tawadlu'.

Evidence for a Minor Gene–for–Minor Gene Interaction Explaining Nonhypersensitive Polygenic Partial Disease Resistance

Partial resistance is a quantitative type of resistance that, by definition of Parlevliet, is not based on hypersensitivity. It is largely pathotype nonspecific, although some minor isolate-specific responses have been reported. In order to elucidate the isolate specificity of individual genes for partial resistance, three barley recombinant inbred line mapping populations were analyzed for resistance to the leaf rust fungus Puccinia hordei. The mapping populations were inoculated with one isolate avirulent and two isolates virulent to resistance gene Rph7g. Six significant quantitative trait loci (QTLs) were detected. Of these, two (Rphq3 and Rphq11) were detected with only the avirulent isolate (1.2.1.) and one (Rphq18) only with both virulent isolates (CO-04 and 28.1). The effectiveness of these QTLs was tested with 14 isolates, using a tester set of genotypes containing alleles for resistance or susceptibility for these QTLs. QTL Rphq18 was effective to only two isolates, CO-04 and 28.1, whereas Rphq3 and Rphq11 were ineffective to CO-04 and 28.1 but effective to all other isolates, except one. This resulted in a significant Person's differential interaction, which is a hallmark of a gene–for–gene interaction. The minor gene–for–minor gene interaction is not based on hypersensitivity and there is no evidence that the resistance is based on genes belonging to the nucleotide-binding leucine-rich repeat class.

Development of Pinus koraiensis SSR Primers Based on EST-SSR Information Technology

A total 408 SSRs were distributed in 18,181 ESTs sequences in Pinaceae in NCBI (National Center for Biotechnology Information) searched by SSRIT software, accounting for 2.24% of the whole EST sequences. We designed 132 pairs of EST-SSR primers by primer3. Of the designed 132 pairs, 29 pairs were able to produce an amplification product in the 10 Pinus koraiensis DNA samples, but only five primers in the 29 pairs exhibited polymorphism. Dinucleotide repeats were the most common repeat class. The repeated primitives of dinucleotide were 10, accounting for 52.73% of the whole repeated primitives; the repeat numbers were 87. The second most common repeat class was trinucleotide. The repeated primitives of trinucleotide were 27, accounting for 42.27% of the whole repeated primitives, and repeat numbers were 78.

Molecular organization of 5S rDNA in sharks of the genusRhizoprionodon: insights into the evolutionary dynamics of 5S rDNA in vertebrate genomes

SummaryIn this study, we attempted a molecular characterization of the 5S rDNA in two closely related species of carcharhiniform sharks,Rhizoprionodon lalandiiandRhizoprionodon porosus, as well as a further comparative analysis of available data on lampreys, several fish groups and other vertebrates. Our data show thatRhizoprionodonsharks carry two 5S rDNA classes in their genomes: a short repeat class (termed class I) composed of ~185 bp repeats, and a large repeat class (termed class II) arrayed in ~465 bp units. These classes were differentiated by several base substitutions in the 5S coding region and by completely distinct non-transcribed spacers (NTS). In class II, both species showed a similar composition for both the gene coding region and the NTS region. In contrast, class I varied extensively both within and between the two shark species. A comparative analysis of 5S rRNA gene sequences of elasmobranchs and other vertebrates showed that class I is closely related to the bony fishes, whereas the class II gene formed a separate cartilaginous clade. The presence of two variant classes of 5S rDNA in sharks likely maintains the tendency for dual ribosomal classes observed in other fish species. The present data regarding the 5S rDNA organization provide insights into the dynamics and evolution of this multigene family in the fish genome, and they may also be useful in clarifying aspects of vertebrate genome evolution.