ABSTRACT. Melon (Cucumis melo L.) is an important species in the cucurbit family with a large economic importance in the world. Two melon cultivars commercially important in Brazil are ‘Yellow’ and ‘Gaúcho’. In addition to their economic importance, these two cultivars display phenotypic differences in aroma, a major trait determining fruit quality. Volatile organic compounds (VOCs) impart the different aroma found in this fruit and their biosynthesis is associated with fatty acid and amino acid metabolism. Using RT-qPCR techniques, the expression of seven genes (CmLOX9, CmLOX18, CmBCAT1, CmArAT1, CmPDC1, CmADH1, and CmAAT1) was determined during ripening. The lipid pathway played a strong role in determining aroma composition in non-climacteric ‘Yellow’ melons. Most volatiles decreased during ripening, explaining the non-aromatic characteristic of this cultivar. In climacteric ‘Gaúcho’ melons, the amino acid pathway was the main one related to the biosynthesis of esters, which contribute to the aroma of this cultivar. Volatile products of the branched-chain amino acid pathway correlated with CmADH1 and CmAAT1 expression, demonstrating their role in volatile synthesis in this climacteric melon cultivar. In addition, CmPDC1 contributes to the formation of aldehydes at the beginning of this pathway. ABSTRACT Cucumis L. L world ‘Yellow Yellow ‘Gaúcho. Gaúcho ‘Gaúcho . quality VOCs (VOCs metabolism RTqPCR RT qPCR techniques CmLOX9, CmLOX9 CmLOX (CmLOX9 CmLOX18 CmBCAT1 CmBCAT CmArAT1 CmArAT CmPDC CmADH CmAAT ripening nonclimacteric non melons nonaromatic aromatic cultivar esters branchedchain branched chain (CmLOX CmLOX1

Abstract Neotropical fishes emerge as an extremely diverse group of vertebrates where genomic strategies to evaluate structural and functional features are still beginning. Here, we present a second draft genome of Apareiodon sp. (2n=54, ZZ/ZW), adding PacBio technology whole genome sequencing, and assembling by combining two technologies (long and short reads). Using a detailed strategy for genome assembly with fish genomes of Pygocentrus nattereri, Carassius auratus, and Astyanax mexicanus as references, the final assembly of the Apareiodon sp. genome generated 93 scaffolds, an N50 of 37,200,078 bases, and a size estimate considering 28 scaffolds (26 autosomes+ZW) of ~945 Mb. In Apareiodon sp., this second genome draft confirmed that ~36% of the genome is composed of repetitive DNA. Furthermore, the new draft genome has improved genomic quality assessments, allowing the annotation of 36,290 genes and 15,683 proteins, which presented similarities to reference genomes. The second draft genome of Apareiodon sp. will be useful for research on integrative cytogenetic and genomic data. It will open perspectives for analyzing sex-determining genes in Neotropical fish with a ZZ/ZW sex chromosome system. beginning Here sp 2n=54, 2n54 n 2n 54 (2n=54 ZZ/ZW, ZZZW , ZZ ZW ZZ/ZW) sequencing long reads. reads . reads) nattereri auratus references 9 N N5 37200078 37 200 078 37,200,07 bases 2 26 (2 autosomes+ZW autosomesZW autosomes 945 ~94 Mb 36 ~36 DNA Furthermore assessments 36290 290 36,29 15683 15 683 15,68 proteins data sexdetermining determining system 2n=54 2n5 5 (2n=5 3720007 3 20 07 37,200,0 ( 94 ~9 ~3 3629 29 36,2 1568 1 68 15,6 2n=5 (2n= 372000 0 37,200, ~ 362 36, 156 6 15, 2n= (2n 37200 37,200 3720 37,20 372 37,2 37,

Parodontidae fish show few morphological characteristics for the identification of their representatives and chromosomal analyses have provided reliable features for determining the interrelationships in this family. In this study, the chromosomes of Apareiodon hasemani from the São Francisco River basin, Brazil, were analyzed and showed a karyotype with 2n = 54 meta/submetacentric chromosomes, and a ZZ/ZW sex chromosome system. The study revealed active NORs located on pair 11 and additional 18S rDNA sites on pairs 7 and 22. The 5S rDNA locus was found in pair 14. It showed a pericentric inversion regarding the ancestral condition. The satellite DNA pPh2004 was absent in the chromosomes of A. hasemani, a shared condition with most members of Apareiodon. The WAp probe was able to detect the amplification region of the W chromosome, corroborating the common origin of the system within Parodontidae. These chromosomal data corroborate an origin for the ZW system of Parodontidae and aid in the understanding of the differentiation of sex chromosome systems in Neotropical fishes.