Influence of Nucleic Acids on the Synthesis of Crystalline Ca(II), Ba(II), and Sr(II) Silica-Carbonate Biomorphs: Implications for the Chemical Origin of Life on Primitive Earth
Por:
Cuellar-Cruz, Mayra, Islas, Selene R., Gonzalez, Gonzalo, Moreno, Abel
Publicada:
1 ago 2019
Resumen:
The Precambrian era is associated with the origin of life on primitive
Earth. It was, in fact, in that era that ribonucleic acid (RNA) was
first acquired. From this evolved the genomic deoxyribonucleic acid
(DNA) that later generated the biomolecules that formed the first cell.
In this way, with the ongoing changes in environmental factors, the
first cells evolved to give rise to higher multicellular organisms,
i.e., plants and animals. Radiolarians and diatoms are organisms that
have been conserved since the Precambrian era. However, although these
organisms are alive (they can be considered as living fossils), they do
not suffice to explain the origin of life. To understand the origin of
life, the interactions among inorganic compounds that existed in the
Precambrian era must be elucidated. In this context, calcium, barium, or
strontium silico-carbonates (usually called silica-biomorphs) have been
simply named biomorphs that emulate the morphologies of organisms, such
as flowers, leaves, stems, helices, worms, radiolarians, and diatoms,
among others. The shapes of the biomorphs can be implicated in the
origin of life due to their similarity with the shapes of the cherts of
the Precambrian era. However, biomorphs are inorganic compounds that do
not contain any organic biomolecules such as nucleic acids or proteins
inside their chemical structures. The aim of the present work was to
synthesize calcium, barium, or strontium silica biomorphs in the
presence of nucleic acids: genomic DNA (linear double helices), plasmid
DNA (circular helices), and RNA (a single chain helix). The morphology
of these biomorphs was assessed through scanning electron microscopy
(SEM). The obtained microphotographs revealed that nucleic acids direct
the synthesis of biomorphs toward a unique and specific structure for
each of these biomolecules. The chemical composition and the crystalline
structure were determined through micro-Raman spectroscopy and X-ray
diffraction to characterize the most characteristic crystalline phases.
The biomorphs obtained from calcium, barium, or strontium corresponded
to crystalline structures of CaCO3 (calcite, aragonite, vaterite), BaCO3
(witherite), or SrCO3 (strontianite), respectively. These
silica-carbonates (considered as reminiscence of the shape found in the
cherts of the Precambrian) can be a linking point between the
Precambrian era and the subsequent eras. To the best of our knowledge,
this is the first report in which the interaction of nucleic acids in
the synthesis of biomorphs has been evaluated.
Filiaciones:
Cuellar-Cruz, Mayra:
Univ Guanajuato, Dept Biol, Div Ciencias Nat & Exactas, Campus Guanajuato,Noria Alta S-N, Guanajuato 36050, Mexico
Univ Nacl Autonoma Mexico, Inst Quim, Av Univ 3000,Ciudad Univ, Ciudad De Mexico 04510, DF, Mexico
Islas, Selene R.:
Univ Nacl Autonoma Mexico, Inst Ciencias Aplicadas & Tecnol, Circuito Exterior S-N,Ciudad Univ, Ciudad De Mexico, Mexico
Gonzalez, Gonzalo:
Univ Nacl Autonoma Mexico, Inst Invest Mat, Av Univ 3000,Ciudad Univ, Ciudad De Mexico 04510, DF, Mexico
Moreno, Abel:
Univ Nacl Autonoma Mexico, Inst Quim, Av Univ 3000,Ciudad Univ, Ciudad De Mexico 04510, DF, Mexico
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